If someone’s productivity slips from wfh then address the issue sure.
There's absolutely nothing wrong with that. That's what I've been strongly advocating for during the last 2 years. Go out there and live your life normally as you see fit.
One problem is that at least some people out there are trying to milk Covid-19. Publicly, they tell their employer they're too scared of Covid-19 to come to the office so they get to stay home. Privately, they go out every weekend and interact with people normally and live their life.
Agree with your second point though. There's even people absuing remote work to work multiple jobs simultaneously.
Given how political worldview seems to be pretty correlated with concern about stuff like Covid-19 and the new labor movement that has emerged, I'd suspect that it's reasonably focused.
Nobody can read minds of course, but I think it is smart to not always take people at face value and consider all of their motives in saying anything. Personally I think Elon Musk is probably strongly supporting working in the office for 2 reasons. (Obviously pure speculation)
1) Forcing an ultimatum is a means of achieving a stealth layoff. Tesla probably wants a few percent of people to quit and trim expenses without losing investor confidence, as their stock price is of course inflated. (My prediction is that many businesses are probably going to be needlessly promoting working from the office to try and effectively achieve a round of layoffs by having a percentage of people quit)
2) The people who are the loudest about working from home probably are the biggest workplace trouble-makers about relative non-issues. To give an example: I know that this is genuinely a sensitive issue for some, but we all know that there are at least some people who are loudly trying to milk Covid-19 for eternity so they can stay home from work and meanwhile are going out to eat at restaurants and living life care-free.