[Snowdax]

Stability is a concern because startups are not stable. In 6 months time Apple could open source something that makes your last 5 years of work irrelevant in a night. If you can't ship in 6 months you're company will probably have shut up shop in 12 because someone already ate your lunch.

If it's a choice between stability (via proper testing, architecture, etc.) and staying operating, stability loses every time.

No matter what happens the tech world is a different place in a year. You have to adapt regardless so properly thought out code will get thrown out just as easily as 4am hacks.