Even if the old software/ROMs were available
Not having the original controls, and emulators that don't work properly or run too fast / too slow make them no fun to play. It seems to be impossible to get a good joystick these days. You definitely can't get one that's the equal of the ones the old arcade games had, but even getting one that's of the same quality as Atari 2600 joysticks is pretty difficult nowadays.
And nevermind games that had controls other than a joystick.
Not being able to get the original ROMs is a blessing in disguise, because when you try to actually play one of these games you'll get frustrated in minutes by how the shitty controls don't work like they should or how everything is moving in slow motion or at warp speed (and sometimes both depending on how much is happening on the screen)
I've got a friend who has a few of the original arcade cabinet games that are still working, and he has played with just about every emulator there is. He gave up on them, and that's why he spend thousands on the original arcade versions because everything out there sucks. I think the people who don't think they suck aren't old enough to played the games when they were new so they don't know what they were missing. They just assume "well this kinda sucks but that's what I would expect for something that was running on a few KB of memory on a 1 MHz CPU, and my dad talking about how great it was is just because he had really low expectations". They don't know how good some of that old school stuff really was running on the original hardware.