I feel like pivoting got unwarranted hype in the 2010s or so, possibly because Slack was an outlier in how successful they were.

Major pivoting is almost always a really bad idea. (I admit I'm doing a bit of weaseling using the "major" qualifier, but when I searched for examples online, a lot of the ones that came back weren't major pivots, just slight refinements of focus to find better product market fit). Pivoting usually carries a lot of baggage - better to just give the money back and start afresh most of the time.

He might not have had that choice. Investors can put money into a bank account, and just as easily take it out. This is what happened in the 2000 dotbomb.