You should take this as a data point where your gut intuition has failed you.
replyIt is really condescending to dismiss their choice as motivated by vanity rather than assuming that other people might have done their homework and made a rational decision. It might very well be that you have done your own homework and it doesn't make sense for your situation, but other people face different tradeoffs which make it worthwhile.
You need only have read the HN front page 4 days ago to have seen one reason why 50,000 people may be motivated to get solar. Nothing trendy going on there, just poor regional planning.
replyPeople are rarely willing to spend five figures on something just to be trendy or green.
replyJust looking into it for my house in the UK (read, not very sunny) and it'll pay for itself in around 6 years. Seems like a no brainer for a house I'm not planning on moving out of.
replyWhat alternatives do you have in mind that also have an ROI for the homeowner?
replyI'm not the one to whom you asked the question - I can think of plenty of things, but by and large most of the home things with ROI make the most sense to invest in when you're buying a new thing anyway - e.g. solar panels when you need a new roof, EV when you need a new car, ventless dryer when you need a new dryer, heat pump when you need new heating/AC, etc.
replyOff the top of my head the only thing that's really doable without replacing a depreciating asset are certain kinds of insulation upgrades. (And I guess potentially ceiling fan installs.)