I think it is unreasonable to expect a provincial parks system to achieve the level of enforcement and regulation of a national park. Limiting overnight campers won't reduce the crowds as the vast majority are daytrippers, nor will any park-based regulation reduce complaints about areas such as Semaphore Lakes.
Not to mention the fact that regulating or restricting daytrippers is unheard of for 99% of the trails of national parks. When it does happen it isn't for something as mitigatable as "not enough parking on a sunny holiday weekend".
Agree that it's not likely we can reach the same level as US National Parks, but we can get somewhere, if we're willing to try.....otherwise we get nothing.
We started this thread talking about day hikers at Joffre Lakes but moved into a discussion about "polluting" the backcountry. I agree that what I have proposed will not help with day hikers but it will help with overnight campers, who probably contribute the lion's share of pollution. If people have to reserve a backcountry campsite, often by lottery, and limit the "users" it is highly unlikely that they will be the type who indiscriminately despoil and pollute the environment.
I agree that we can't solve all the problems in all the areas but we have to start somewhere.