You aren't the only one. There are certainly pros and cons of every option. A few years ago, I would have opted for not doing anything in hopes that it would remain a relatively unknown location. However, I don't think that is a reasonable plan anymore. Semaphore Lakes is widely known. It is the 5th hike in the book: 103 Hikes in Southwestern British Columbia. It is also in the Scrambles book. With social media and internet sites (this one included,) the cat is entirely out of the bag. I have a datapoint for one weekend this summer: there were over 30 cars parked at Semaphore Lakes trailhead! I also think it will get worse. In response to the Joffre Lake overcrowding, no-parking signs have been installed in the last week or two along the highway. That will push people to other destinations including Semaphore Lakes. It means that some investment is now required (trail improvements, outhouses at a minimum). The government has taken a number of steps this year to limit access in response to increased demand (backcountry camping reservations, limiting parking, etc.) Although those may protect one area, it just moves the problem to the next. Because Semaphore Lakes has no status (it is not a rec site, a conservancy or a park,) it is particularly vulnerable. Unless the increase in demand is matched with an investment in trails/facilities in one location or another, the problem is not actually being dealt with.
Of course, I also want to emphasize that this "problem" is actually a reflection of a positive opportunity. There are a lot of good reasons (economic, social, environmental) why we want people to be coming to BC, staying in BC and enjoying our outdoor areas. We spend a lot of money promoting these activities so we need to match that with a small investment to make sure people can actually engage in those activities.
Re motorized activity in the winter. The area is actively used in the winter by snowmobilers and commercial ski operation(s). There is a land and resource management plan in place already and that would be used to provide guidance on those activities once the land becomes a park. Trying to re-open all of that would be a much larger change that is unrelated to the summer issues and would likely face a lot of opposition.
The road is often rough but I would hesitate to suggest it is deteriorating year over year. Because it is an important link to a number of communities, it is continually maintained. I have even seen a newer model Mercedes sedan on the road (not recommended during a lot of the year!)
You can see the updates here and note that there is a lot of active work happening (grading, signage, brushing, etc.)
As mentioned above, I've heard of over 30 cars at that trailhead this summer so I think it's safe to say that the weekend warriors have arrived.