If anything, I tend to judge people a little bit who stay in the same place more than 3-4 years in this industry. Staying somewhere that long you end up with very insular views and limited exposure to new tech and ideas outside of your bubble, and beyond that, I am a bit wary of someone who isn't motivated by the financial incentive of a diagonal upgrade every 2-3 years, or somehow doesn't see that potential. Being able to effectively advocate for yourself and by extension your ideas I see as an essential skill for SWE.
Also, I think failed startup experience is super valuable, perhaps more valuable in some cases than coincidentally riding a unicorn and now falsely believing that every little thing you did along the way (or your cherry-picked list of "favorite" things you did) is actually repeatable, useful advice and/or a blueprint for future success.