Apple’s focus on thin:
Essential for making technology “transparent” and as unobtrusive as possible.
Having to connect hubs and dongles to get the ports you need because they've been removed from the computer to save space isn't "transparent and unobtrusive".
Having to type on a keyboard which is, at best, "love it or loathe it" and at worst just plain unreliable because its been made thin to save space isn't "transparent and unobtrusive".
Needing an eGPU (and hence, an external display) to get the type of GPU you need
even on a desktop system isn't "transparent and unobtrusive".
Having to reach round the back of a 27" iMac to plug in a SD card or USB stick is
certainly neither transparent nor unobtrusive.
Need a powerful Mac? See: iMac pro. If that isn’t enough power, you need a supercomputer, not a desktop workstation.
"powerful" isn't just about how many cores the CPU has. Versatility plays a role, too. The big problem with the iMac Pro is that it comes with Hobson's Choice of a 27" 5k glossy display with a particular colour gamut optimised for video editing (oh, and, lousy ergonomics unless you buy a VESA stand and a $80 VESA adapter with screws apparently made of cheese). That display is
great value if it is exactly what you want but
worthless if (say) you prefer a matte display, an ultrawide display, a 40" 4k display, a matching pair of 21" displays, a different colour gamut, a display with a hood and builtin colorimeter or the really expensive display that you bought 3 years ago and is good for another 5-10 years...
...and see note above about eGPUs, while also bearing in mind that (for example) some people need NVIDIA GPUs because they run software that works best with NVIDIA.
Some of us don't even
need Xeon-class CPUs but still want flexibility in terms of GPU choice, external storage and connectivity... the top-spec regular i7 iMac is powerful enough for many.... except, as soon as you start taking advantage of the i7 power you're hit with the noise that comes from pumping large quantities of cooling air through a thin'n'crispy case.
E.g: music. I'm only messing about with this for my own satisfaction but its one area where Macs are still widely used professionally (and MacOS is regarded as better than Windows). A lot of music hardware - even brand new products just released - comes with a USB
2 interface for MIDI and config/firmware... not USB C, not USB 3 not Thunderbolt (apart from some high-end stuff with a gazillion 192kHz audio inputs) - it doesn't need the bandwidth, but nor does it want the extra latency, instability and sleep problems that you get with a hub.... nope, you want half a dozen extra USB2 ports straight off the motherboard (which you'll get with many desktop PCs) or from extra USB controllers on PCIe cards (I don't currently see any Thunderbolt-to-shedload-of-USB adapters, and they'd still be an extra box and wall-wart).
...also a case of where the i7 in the iMac would be fine for most purposes if it had space for a silent cooling system.
Apple is dumb for dropping ports on the MacBook Pro:
A notebook is a PORTABLE computer.
...so you don't want to have to rummage in your bag for a dongle every time someone hands you a USB stick, or carry around a portable hard drive holding the videos you want to show (or take out a second mortgage to pay for more than 512GB of internal, mostly non-upgradeable SSD). Plus, while we'd already resigned ourself to not having space for a VGA socket in our MBPs (still the most common requirement for hooking up to a data projector) we were
just getting to the point where meeting rooms were starting to sprout HDMI connections (or even a MiniDP adapter) when that connection was whisked away from the MBP. Clearly, some people live in a world where their flunkeys have scouted the location and installed hot and cold running Apple TVs before they step up on stage.
My only impression of seeing one in use was on a TV show where Prince William received a FaceTime call from Lady Gaga on his MacBook Pro, and used the touchbar to answer the call.
If you think that they were filming Prince William when Lady Gaga
just happened to FaceTime him and he just reacted naturally, then I have a bridge in London for sale that you might be interested in. (Seriously, even if it did happen spontaneously, they'd probably re-enact it to get the correct camera angles anyway, and a half-decent video editor can drop in a swift cut-away over any hunting, stabbbing and cussing so slickly that you'd never notice). Rule 1: the camera
always lies. If its TV, its not reality.
That said, I really must get a TouchBar, because Lady Gaga never returns my calls.
Seriously, though, (a) that's one scenario that a touch
screen (something that most of the MacBook's competitors are now offering
alongside a keyboard and trackpad) would be useful (I've been interrupted, a pop-up has grabbed my attention and I want to press the 'accept call' button on it without having to think how to navigate to it)
(b) Even if the touchbar has its uses, is it a good differentiating feature for a
pro laptop? On the one hand, there's been no apparent rush to implement it on the 12" MacBook, where you'd expect the target users to be more worried about missing FaceTimes from minor celebrities than "how am I going to hit the escape key when I'm using
vim" nor to implement it on an external keyboard for the iMac Pro (I can see the challenges of doing it on an external device, but I dinnae think it breaks the laws o' physics and Apple is supposed to be where the magic happens).
There's a problem with introducing a user interface convention that isn't going to be rolled out
across the range to make it worth developers' while to support it (see also: force touch and Pencil support on iOS).
Touchbar strikes me as a great iPhone/iPad app that - if implemented well - would help distinguish the whole Mac/iOS ecosystem from the competition... that's certainly not incompatible with what we've heard about Apple's pro workflow team, but where's the App? That report was talking about things like Logic Remote which
are really cool (walk around the room tweaking the EQ on Logic depending on what you hear...) but that's been around for years.