And just how, exactly, would forcing players to complete a series of simple(to bronze) challenges that teach you a very tiny bit of car control while teaching virtually zero race-craft or driving etiquette and then culminate with several tests of your ability to plow your way through a whole field of cars in a very short period of time have any effect on whether or not people find such behavior online amusing?
I still can't for the life of me understand why people think license and/or game completion level restrictions would do anything to improve the attitude of video gamers playing online. Even if it actually did require you to be quite fast to pass the tests or clear the game, the people playing would still act the same. Putting higher restrictions on contact wouldn't change anything either, people would just do what they have to do to get through and some might even think "good, now I can finally have fun(translation: hit people)!" All such restrictions would accomplish would be to limit people's legitimate enjoyment of the game, particularly if they aren't that fast(which doesn't mean they don't drive clean), or are starting over from scratch or simply can't stand doing license tests.
It might not be a terrible thing to allow people to set entry restrictions like that on their specific rooms(though I'd argue it would likely still actually accomplish virtually nothing and would provide a new excuse for trolling). But an overall restriction for online would be silly and might well alienate people PD would like to sell the game to. People always seem to forget that those who want to play with no rules, or flat out smash each other up or who have horrible car control skills have every right to enjoy the game too. Kick them, leave their rooms, drive yourself crazy trying to educate them, attempt to find clear track away from them, support good rooms that don't have them, come to threads like this one to vent about them, whatever works. Don't get too worked up about people who don't play like you do. There's always tomorrow, or ten minutes from now.