Well, since this was honestly asked, as opposed to "Why don't we swan dive into the cesspool," I'm happy to relate my experience, and the opinions derived, thereof.
First of all, I don't have an axe to grind, re: RMS. I'm grateful for his contributions, and find some of what he says a bit annoying (but not something I lose sleep over). I honestly don't care whether or not he sits on the FSF board. It has almost nothing to do with the day-to-day work I do.
> but has he actually harmed anybody? Committed any crimes?
Well, the actual question was "Committed any crimes?", verbatim, so answering, by referring to the law of the land (or lack, thereof), is quite understandable. We live in a time, where "If it's legal, it's gold." seems to be the modus operandi of the business world. I find that we spend precious little time, considering such trivialities as Honor, Integrity or Honesty, when looking only at the legal code.
As to "harming someone," I suspect that we may not be the best judge of that. I deal with highly traumatized people, several days a week, and am quite aware of the grievous harm that can be done by folks, not intending to do harm. Often, the most damage is done by simple words (or lack of words), from those in a perceived position of authority (like parents or bosses).
> Obviously yes, saying dumb things will get you criticised and people may think you're a dick.
When people in positions of authority (and RMS is definitely an authority, whether or not he sits on a board) say stuff, it has a lot of impact. In my extracurricular world, I also spend a lot of time, running around with baby wipes, and a pooper-scooper, cleaning up emotional and physical damage, caused by the careless words of folks with authority that refuse to take Responsibility for their positions of influence. I have been one of those people, and have caused damage, by careless words.
I get rather peeved at people that have achieved some position of influence, then disregard the considerable Responsibility that comes with the trappings of power. Like I said, a bricklayer can spout off a bunch of guff, but their bosses are morally (and sometimes, ethically, and even legally) Responsible to watch what the heck they say. Today's hyper-connected world makes this even more imperative. Jerome Powell can crash the stock market by taking off his glasses to rub his eyes.
I really wish that society did a better job of teaching simple ethics, courtesy and logic. As someone who actually has a somewhat diminished capacity for this, I have had to learn it from scratch; often the hard way. I have caused a lot of hurt and embarrassment, over the years, been held to account, and have had to apply a great deal of self-discipline to mitigate my natural inclinations. It has not been fun. It's difficult for me to be sympathetic to folks that should have it come natural, and I know, for a fact, that there is a better way.