If your kid is quiet and keeps to themselves, then I haven't even noticed them in the first place in order to take issue. The reason I take issue is because your kid is being loud or obnoxious and ruining my experience in (grocery store | restaurant | movie theatre | public transportation | anywhere that I'm politely minding my own business but your kid is forcing me to know that it exists).
As people like to say when discussing rights and freedoms: your rights end where my nose begins.
My wife and I recently travelled to Walt Disney World for a vacation. While in a hotel lobby we walked past a child around 8 or 9 years-old (if I had to guess) accompanied by a man that I assumed was his father. As we walked past, the kid punched my wife in the arm. It wasn't a mistake. He telegraphed the hell out of it. When I confronted the father he just smiled and shrugged it off.
If people didn't constantly have to deal with situations like the above, then we could talk about being more tolerant towards other peoples' children.
But if it's not a child invading physical boundaries, it's auditory. God help those of us with misophonia that have to listen to children make the most hideous noises (and not always due to a temper tantrum, sometimes it's just loud screeching or yelling as part of play or whatever).
Why should anyone have to tolerate this? And no, I don't blame the children, I blame the parents. But who is at fault is irrelevant. No one should be obligated to put up with assholes whether those assholes are 40 years-old or 4 years-old.
Another way of phrasing this is more people are choosing not to have children - one motivation probably being that they can actually be quite a nuisance, a sentiment I've heard from literally every parent I've ever talked to.
Parents do deserve to go to all kinds of events - and generally are allowed to. Parents do not have the right to disturb events for people who choose not to have kids.