Don't know if you're a motorbike rider I can't the words to make you understand, just like big scoots are 350cc it so they are scoots not big motorbike in terms.
As far as accidents go a wave or scoot and someone that rides a big motorbike age comes very much into the fact.
As for big motorbike speed that can keep you safer and again if you are not a big motorbike riders you won't understand.
To ride a Wave in Bangkok does take experience to stay alive I agree.
I thought it was something simple enough to work out for yourself that is, kids go off to school on Waves and scoots because it's convenient for parents to let them so to inforcement laws would be unpopular.
Disagree with your logic and what I think and what will be done is something I can do nothing about.
I'm going on my bike now and more than lightly will break the speed limit in 1st, get to where I go have a couple of beers and come home again as I have done in UK and now in Thailand since I was 14 yr old, have a nice day.