I'm guessing that griping about RMDs has been going on for as long as RMDs existed. I remember my Grandmom complaining about them back in the mid 1990s. Back then I didn't understand them, so I was siding with her at the time, thinking why should she have to withdraw the money if she doesn't need it. But, once I got a bit older, and had enrolled in my first 401k, I finally got it. The idea that the gov't is giving me a tax break now, letting it grow tax free, but at some point, they're going to want something in return. So, once I understood it, it seemed fair to me.
I remember my Mom starting to carry on as well, when that first SECURE Act, or whatever it was passed. The one that upped RMD age from 70.5 to 72. She just missed the cutoff and had to start RMDs at 70.5. And she was MIFFED! I tried to explain to her look, you got a tax break when it went in, you didn't pay taxes as it grew, so you're still getting a nice benefit. She was like, reluctantly, I guess.... But she was still annoyed. And, like my Grandmom, she was also annoyed because she didn't need the money. I told her that just because she withdrew it, doesn't mean she HAS to spend it. She could invest/save it somewhere else.
I think people just don't like it when the government tells them what to do. And, forcing an RMD on someone is the government telling them what to do. Nevermind the fact that it was an agreement you made, when you started that 401k/IRA in the first place.
I'm not sure if I'm going to do Roth conversions yet, but I am planning on starting to take withdrawals at 59.5. I ran my numbers through an RMD calculator, and if I was 75, the amount I have in my rollover-from-work IRAs and 401k would give me an RMD if around $70K the first year. But in reality, I have 19 years before I turn 75. So in 19 years, that total could blow up something fierce.
I have one rollover IRA, from a previous employer, that I stopped contributing to in May of 2009, when I switched employers. Since then, its value has blown up 6.38X ! While that's no guarantee for the future, if it did that in 16 years, it's conceivable my total could blow up by that much or even more, in 19 years.