Well put. I would say that things have changed since even an year ago. Nowadays, if you are building a MVP and plan on a closed beta launch - expect moaning & groaning about your unpolished UI. People just expect well-designed experiences from day 1.
Thanks for the feedback and good point. I'm actually kind of torn on the importance of design. I think the sentiment is that you are competing with designs of the popular sites that people already use (e.g. NYT, Google, Facebook, etc.), but I think that people are fine if things are rough around the edges -- even if they moan and groan. As I said, though, it ultimately all needs to come together.
I agree with your point. IMO its all about communication. Currently, I am building a product with somebody and between the both of us the wireframe is more than sufficient. But, after 2 weeks of coding we started showing it to our friends and instantly we could see the ranges of communication errors - some got it despite the 'bad ui', some just could Not look beyond the ui fails, some were kinda sorta struggling.
Yup, communication I think is separate from UI (sort of in between UI and IA), it's going to be its own post entirely, I think it is incredibly, incredibly important and can only really be done after getting your hand in users' hands or really understanding the points of confusion (which is hard, since you know what your product does and how to use it)
I recently tried a beta for a company that received wide acclaim, won a bunch of competitions, and appeared on Tech Crunch. Yet their product had a lot of big bugs. You know, the kind that slow down your computer and make you worry about data loss. Fun stuff like that. It was clear that they decided to launch the beta even though they had to have known about these serious bugs. That's what you should bitch about.