Completely agree with the ideal situation you present. The problem is that this doesn't hold up under the pressures of small teams chasing high growth.

Nobody is intentionally sabotaging anyone else (usually) but everyone stretches a little bit in the name of growth and things break down at the edges. Revenue growth can be life or death for small companies so, even though it sucks, promises are made and things are rushed. A perfect foundation and completely bug-free features don't matter if the business is dead.

There's a lot of sub-optimal juggling going on around this growth phase where you sometimes need to just focus on keeping the ship afloat until you hit the next set of milestones -> prove your worth -> raise -> grow the team to help shore up the foundation. Even if you aren't raising VC it can still be a similar grind where you need more cash flow to hire more to meet the exploding customer demands.

I will note that this only applies to high growth companies. If you have a pile of cash, strong product conviction (and skill), and the willpower to keep your feature set limited while turning away potential customers, you might be able to build the solid foundation -> sell the rock solid product. That isn't how most startups operate though and once you take VC the clock is ticking.