Having a publisher helps a lot. But 4000 copies for many indies would be a rousing success (albeit, not a financial success). It is simply that competitive.
>I could also see a wife being upset her previously highly paid husband is working on a video game, and presumably a low salary from a publisher (if any).
Very true for 99.99% of indie devs. But I figure that OP's savings and RSU's (almost a deacade's worth) would easily put them in a situation everyone else can only dream of.
>When I was working on my previous startup...
I know startups are risky, but I really don't get this attitude. It might just be lack of knowledge, but once you can get a startup off its feet, the VC money from seeds easily makes up for that downtime. And unless you're the founder or are a near-founder being paid with future equity, startups can still pay very respectably. It's the time committment that you need to worry about.