The real issue and problem here is that these are two totally different markets... one is an all-in-one computer, and the other is a stand alone display and trying to compare the cost of each is a little ridiculous.
It's not "two totally different markets" for 27" iMac users who's only like-for-like upgrade path is suddenly to buy "separates" (to borrow the Hi-Fi term) at a substantially higher price, with only minimal improvements in display quality.
I don't think the people who were already in the "separates" systems market have anything to complain about - they can keep their existing displays, and if that means an LG Ultrafine, decide for themselves whether the Studio Display is a worthwhile upgrade... and part of the reason they
were using separates might be because 27" @ 5k wasn't their preference, anyway.
Especially considering the quality and feature set of the Studio Display as compared with other computer displays on the market.
Except that boils down to (a) it looks swish, (b) it's one of the very few choices if you want 5k @ 27" because you've been 'spoiled' by an iMac and (c) nice speakers - but probably no substitute for external speakers & redundant if you're using an external audio interface. Apart from that, it's all iffy - limited stand, buggy webcam, silly fixed mains cable.
Hmmm... why didn't you buy the 5K LG? Seems like the exact display you want!?
Except they're currently as common as rocking horse poo so you probably
can't buy one, plus, you're still paying for a Thunderbolt dock, ~100W power supply, so-so quality webcam, speakers, mic. etc. Also, both lack one feature missing on virtually every competing display: multiple DisplayPort and HDMI inputs so you can easily plug other equipment into them without cable juggling.
It's essentially a take on the same concept as the Studio Display - just a little bit worse all-round - and the standard-def Thunderbolt and Cinema displays before it - and that concept is
really a laptop docking station rather than an external display for a desktop computer. It's not really an
alternative.
If you use external speakers & audio interface (e.g. anybody doing music/AV production which is a
major segment of the higher-end Mac market) the speakers are pointless. If you want a
decent quality webcam, that will be separate. If you're podcasting etc. you'll want a proper ext. mic (& probably audio interface => external speakers). If you are using a desktop system then the ability to power a laptop is redundant.
...and, of course, if you want a
dual screen setup, well - quadraphonic sound and 3D Zoom meetings anybody? Nah, didn't think so.
...and if you
do want that all-in-one convenience? Well, we're back to all those 27" iMac users who've just been thrown under a bus.