I think the short answer is “sometimes.” One time they are not stupid is when a multi-story structure replaces a flat parking lot in the center of a city. Flat parking lots are such a tremendous waste of a precious resource... land. Land that could be used for housing and café’s and shops and workplaces and key public facilities.
It would be kind of stupid if we had a chance to use that land to build affordable rental housing and failed to do so --since affordable rental housing is the single greatest need our community has right now. And (though there is much more to be said about this) creating multi-unit housing in a downtown area is the smartest location because it makes it easier to live without a car. And because some of the people living in prospective new rental housing down will still have cars, it will be a more efficient use of the parking spaces we have. They can be shared between downtown workers, downtown residents and downtown visitors.
Frankly, I don’t want to wade into the downtown library/parking structure controversy because the library is not a key issue for me. However I almost always want to wade into local housing issues. And I hope the library/parking structure discussion will focus on how it will impact affordable rental housing opportunities. This is not a stretch. Even those who want to get our transportation system to shift away from cars and parking lots really seem to care about these housing issues. They could actually take the stand that a parking structure is fine as long as it is used to free up other land for housing and used to create additional shared parking opportunities for downtown residents that still need a car.
Okay, where does stupid come in on all this? Well my stupid part is I’m not toeing the line with my "climate warrior" friends who want to fight against a parking structure no matter what. But the other stupid part is the some of the criticism of city staff people that have been working on one reasonable approach to addressing library, parking and housing needs through the proposed parking structure. Some critics seem to find something sinister in the city staff’s approach. I think that is an error. I think it's probably stupid to demonize human beings that are not just doing their jobs but really trying to solve some real challenges in their community. (Yeah, they live here, too.) The staff people might be missing the mark but they are good people trying to do something positive. If one doesn’t like their proposals, it is totally fine to propose something different and/or better. But knock of the stupid stuff.