My recollection is that $125k came about because when there was more money (and there was at one time) it was enough to tempt a non-trivial number of founders to fight over rather than build a company.

The problem, in so far as what I read on HN, was not three cofounders deciding to take the money and travel the world instead of building the company. The problem was that the founders who were interested in fighting over the money were distributed across many teams.

As for the realism of six months of expenses from $125k, thinking about it those terms is a signal that someone might not be a good fit. If it's a problem, it's a surmountable problem either through work (and luck) or through a willingness to fail.

It's a non-starter for non-startups.