I'm guessing you probably weren't there back then, but there used to be a time when you actually needed to buy yellow wards, and pink ward cost a bit more.
Since you actually had to spend gold, people bought a lot less wards, and it was mostly the support's job.
Nowadays you get free recharging wards just for spawning in and cheap pinks.
I personally think we're at a point where we have a bit too much vision with next to no effort, thinking or investment.
Also most lower elo players don't realise that many wards cover more than only what they show. If I'm bot red side and place two wards, one deep next to red, and one in the river in front of drake, I basically see the whole bot side. With a little map awareness, I'll be fine.
About the limit of wards per person, I find it pretty good. It avoids having the whole map warded, which would make the game a lot less fun in an interactive way. Yes clearing/placing wards is interactive, but is it remotely fun ?
As to the minions, I'm more concerned about the randomness of the AI. The canon randomly changing target, or my melees randomly ignoring the enemy melees and going straight for casters. That's something that should be fixed, as it screws up freezes or wave manipulation every now and then.