It's unfortunate, but also not surprising. These cropped up in some of the most expensive real estate markets on the planet with no particularly good prospect for long-term sustainability.
At first, you have an influx of excited members, so it feels like you have a shot at it - but within a couple of years, most of them drop out. They either get discouraged, or they find their groove and really want the convenience and flexibility of working on their own schedule with their own tools that aren't abused by strangers.
If you want to run a Makerspace in Portland, Seattle, or in the SF Bay Area, you better have an endowment from a wealthy donor, a long-term government grant, or something of that sort.
I would assume that the market for makerspaces is mostly in the centers of cities, where people can't get a big project space for themselves without paying exorbitant amounts of money.
Of course, that market has other problems - cost and neighbors who don't want 24/7 power tool use - but it's better than the alternative where anyone serious about their hobby can easily build their own shop.
ALTSpace in Seattle is still breaking even after twelve years, with no such endowments or grants. As you say, the membership has completely cycled through several times since the start, and there was a major spinoff several years in where several members pulled out to form their own, more private workspace. You have to expect all that and plan for it; you'll need a new generation of leadership every few years, and recruiting new members needs to be an ongoing process.
At first, you have an influx of excited members, so it feels like you have a shot at it - but within a couple of years, most of them drop out. They either get discouraged, or they find their groove and really want the convenience and flexibility of working on their own schedule with their own tools that aren't abused by strangers.
If you want to run a Makerspace in Portland, Seattle, or in the SF Bay Area, you better have an endowment from a wealthy donor, a long-term government grant, or something of that sort.