I disagree. RMS is supremely practical over long periods of time. His core message is "if you tie your fate to something you don't control, you will
get burned." I've never seen this not be correct. Vendors come and go. Sometimes they change their pricing model from reasonable to extortionate. Maybe they discontinue features that were critical to you. Perhaps they throw away the whole thing and start over. But whatever form it takes, the end result is the same: if you can't control it, it will control you.
Apple and Microsoft have probably been the best major companies for keeping their changes small and manageable. Eventually you had to migrate off VB6. Eventually you had to click the "also compile this for Intel" checkbox in Xcode. But that doesn't change the fact that if you use their platforms, you are subject to their business decisions, even when they conflict with yours.
Perhaps hypocritically, I'm typing this on a Mac. I've decided that given Apple's track record, they're probably not going to yank the rug out from under me overnight. But you can bet that all the code I write is in FOSS languages and deployed to FOSS operating systems. I can change my desktop OS - with some pain and gnashing of teeth to be sure - without compromising the things I design. That's because RMS is correct: he's convinced many of us that it's practical to choose open platforms instead of closed shininess where it really matters.