All those suggestions/solutions do work, but the actual problem is still being ignored. At $2000+ then why should we have to make compromises?
Because, at a fundamental level, you don't get to decide not to buy something a company is offering, and then get mad at them for not selling it to you.
Flash is expensive, and upgrades in the industry are always overpriced, and it's more expensive because it's from Apple, and customizability is going to be reduced because it's from Apple.
But the proper complaint is that the 768 is expensive, not that spending $2,000 entitles you not to "compromise" (when, in fact, Apple would view handing you a HDD in a thicker chassis as a compromise).