Would be cool to see example of "Too much railroading" and "Too strict on the rules" that made players really stand up and quit.
One real-life "too much railroading example" was when we had one of the players DMing, he'd written this elaborate adventure and so on (this was just after the first Prism Pentad book had some out, so early '90s), we were excited as prior to me being DM, he'd been a DM, though none of us had played with him then.
We get to the end of an adventure - and finally confront the evil wizard! But the DM has decided that we don't get to fight the wizard, his GMPC does, so he says the wizard gets to go first (even though he lost initiative!), and cast some paralyze-y spell on us (I forget what). My PC is, for some reason, explicitly immune to their spell (item or race, I forget which). Two of the other PCs roll their saves. The DM gets very angry, insists those saves didn't count and that my immunity doesn't protect me - I point out that it literally specifies that spell... eventually he argues us all down, we agree to go along with it, then the GMPC runs in, throws a magic spear, and boom, the evil wizard is dead (one-shot!).
That was the last time he got to DM.
Of course there was an earlier incident, no so much "railroad" as "DM attempts to enforce his own twisted morality on the players" which would probably have made it his last time too:
So usual adventure stuff, then after fighting some orcs we find there are some baby orcs. They are harmless and pathetic by the DM's description (in fact, he emphasized how pathetic they were). So we, being not monsters, decide they're now basically orphans, so we'll take them back to the local church of some nice-guy loves-the-weak deity and they'll look after them (one of us is a cleric there). The DM flips his chips. He never questions the premise, in fact he agrees that said church would take care of them, but he demands that because we are good-aligned, we have to murder the baby orcs. Raising them good isn't enough. They are apparently inherently evil. This is in the FR, where orcs are not inherently evil, just tend that way, note, and that had been established even back then.
So we're just refusing to go with this, and he has his GMPC Paladin turn up, zap all the orc babies somehow (to our utter horror!), and then attempt to tell us off (which was a bit like Genghis Khan trying to explain to some peaceable monks how THEY were the evil ones!). Le sigh.