I think people are frustrated that these "average user" devices seem to be getting more attention and quicker refreshes. The MacBook was updated quite promptly--the same can't be said for the MBP. So when a new device comes out, and it's a MacBook, the "power users" are justifiably disappointed, especially since the device they're waiting for keeps getting delayed further and further.
Additionally, my response to you was geared toward your praise of the MacBook as the "ultimate culmination of the vision of the notebook", which implies that the MacBook is the gold standard to which future notebooks that Apple produces should look toward, and that to me leaves the advanced users in the dark, because clearly this is not a device for advanced users. It seemed to suggest that this thin (yes, "underpowered") core-M device is the "ultimate" Apple notebook because Steve's vision was all about the average user. Go ahead and make more devices like it, but don't abandon the advanced users who really love OS X and prefer it by far to Windows (i.e. me).
And just because I dislike a product, doesn't mean I don't want other people to enjoy it. I can say it's underpowered without implying that it's a bad choice for anyone. By saying it's underpowered, I am saying it's underpowered for me.
I'd rather hope that the delays for the MBP are because they're waiting for more premium parts rather than because they're simply giving it less attention and priority. But we'll see, I guess.
For starters, of course the average user devices are going to get more attention. This makes sense because there are far more average users out there than pros. There are going to be many more people who are in the market for a consumer-grade notebook like the 12" MacBook than there people who are in the market for a 15" MBP with an extremely power quad core i7, dGPU, etc., for instance.
I can understand all of the frustration, but it's not very logical, is it? The reason that the MacBook got a quicker update is because all of the parts that Apple needed to bring the refresh to a fruition were available at an earlier date than the ones suited for the MBP. The processors for the 15" were not even available until extremely recently, for example, and the dGPU's are not available either (if they plan on using one). Going forward this trend is just going to continue because Intel always puts out the less powerful, more consumer oriented products first.
Honestly, I don't think that people's disappointment is all that justified. They are expecting miracles. They wanted Apple to somehow be putting out machines months and months ago when the components just were not there until relatively recently. (I suppose that Apple could have pulled a Dell and used quad cores with GT2 graphics instead of GT4, but that's just not what they do.) If Intel hadn't launched the processors, and they hadn't, then how did people expect these machines in October of last year or March of this year. I think the disappointment will only be justified if WWDC comes and goes with nary a word.
Please note that I did not praise the MacBook as the "ultimate culmination of the vision of the notebook". I think you skewed my quote so that it no longer means what I intended it to mean. What I actually said that I felt that the MacBook was the "ultimate culmination of Steve's vision for the notebook" for the average user. There is a very big difference between those two. I never once said what I thought about it, but rather what I thought Steve's view would have been (he loved thin, light, fanless, fewer moving parts, and so I think that to him there would have been no finer notebook to be found). This is important because of all of those "OMG...Steve would NEVER have done this!!!" posts that we see all of the time that insinuate that Apple has lost all of Steve's vision and values. However, the vision that Apple possesses has always involved their professional machines changing over time to be more like their consumer models in my opinion. The rMBP became more like the MBA in that it jettisoned the optical drive, adopted flash storage, got rid of ports, etc. The next-gen MBP seems like it will adopt key aspects of the rMB and become more like it, as well.
You know, there is a reason why I am so active in the "Waiting for Skylake MBP" thread and it is because the MacBook is not what I need, so it is not the ultimate culmination of the notebook for me, either. I am also one of those advanced users who finds what the MacBook has to offer is just not enough. The screen is tiny, it only has a paltry 8 GB of RAM, the keyboard is just not all that good, one port, it'll probably start throttling down really quickly for me, etc. All that I meant to convey was praise that at least Apple still has a vision of what they think the notebook should be, and not that it's the gold standard of anything. That's it. However, just because this machine is clearly not for me, doesn't mean I am going to rail against it like so many here.
Overall, in my own opinion, I think there is no such thing as an "ultimate notebook" because no one has the same needs. Like I said, I think that Steve would have viewed the MacBook as the machine that all laptops should aspire to be. But, I think that Apple should focus on building the ultimate notebook for consumers and pros (instead of trying to lump them together).
I don't think that Apple is giving the MBP less priority. We aren't talking about the Mac Pro here.
Sorry for the length.