Keyboard working here without issue. Noticed a couple issues earlier on, but discovered was from a couple crumbs. If there were a major issue affecting nearly everyone there would have been a recall or constantly news cycle about it. So I don't think the answer is for others to not buy a MBP because 'you' and some others are experiencing issues. Instead, I'd recommend you and others affected bring it into get fixed.
That being said, I'm sure the keyboards will continue to improve with each generation, albeit with compromises such as to get thinner they change the key styling and eventually will be touch only with haptic feedback (which I'm not excited for) but will be inevitable.
I think you need to reconsider the things you're saying. "A couple crumbs" rendering a key useless is a problem, not something to hand-wave. And yes, the issue is widespread enough that I've read several blog articles, stories, and comments on several websites about how terrible the keyboard is. This isn't some cheap $20 keyboard part that is expected to fail; this is Apple hardware, frequently claimed to be the best in the business.
Why "you" in scare quotes? Do you think people are lying about their problems with the keyboard? People don't want to bring in their workhorse machines (MacBook Pro) for repair because of a couple of crumbs. They don't want to be faced with repairs into the hundreds of dollars. They expect the newer MacBook Pros to be as reliable as the old ones, and this isn't happening.
Why are you so sure the keyboards will "continue to improve" with each generation? They haven't. The current trend is that they're getting worse. Have you tried typing on a hard, flat surface for a lengthy period of time? It hurts. Fingers were not designed to bang against unyielding surfaces for hours on end.
Did you clean them out yourself? There's very little room to use any sort of tool to clean under the keys without removing the caps, and from what I understand pulling the caps is a fairly risky procedure no matter how delicate.
You can get some way with canned air and something like a sheet of heavy paper to slip under the cap, but it's by no means infallible.
My intended solution is to take it periodically to the Apple store and request htey clean it out, since they have replacement caps and presumably the service manual on how to remove them properly. If enough people waste enough of their time and money, it might encourage them towards less hostile designs in future.
> change the key styling and eventually will be touch only with haptic feedback
Seen a lot of Apply apologists super happy about this idea as a sell of "increased reliability because there are less moving parts" when the 2012 model keyboard had zero reliability problems from their moving parts it's only the "butterfly" switch that has reliability problems.
That being said, I'm sure the keyboards will continue to improve with each generation, albeit with compromises such as to get thinner they change the key styling and eventually will be touch only with haptic feedback (which I'm not excited for) but will be inevitable.