The difference being the police plates are situated as best as possible due to vehicle working requirements, (they are REQUIRED to have identifying markers such as the word police and the emergency lights clearly visible. Someone, on a sport bike with their plate tucked under the tail and then bent up so it doesn't hit the rear tire, and is totally obstructed is a CHOICE of that rider, because they are "special and entitled."
The officer does NOT decide, where the plate is located, on the equipment they are provided. If it sticks so badly in your craw, then write to the Commissioner of the OPP with your complaint, I am sure when the bikes were being purchased and designed, it is done so as to be compliant, while still fulfilling the operational requirements. Despite your objections. Now if they place something OVER their plate to conceal the plate that is a different story. I can't comment on the US police bikes as I am not aware of what the law states in each state. The Youtube video, you posted, is also for PERSONAL vehicles NOT government owned vehicles. Those officers, SHOULD be tagged, for their PERSONAL vehicles. I can only comment on Ontario regs.
If they are stopping mass sport bikes at Wasaga, for vehicle equipment checks, that has already been ruled as acceptable by the courts. I guess if sport bike riders didn't as you state, have their plates undertail, (which is clearly a violation), then there would be no need for them to stop to check the bikes and issue tickets for the violations. SO as many have already stated leave your plate where the manufacturer put it and there would be NO need for enforcement. You can't have it both ways... We put our plates in a location KNOWING it is illegal, but also want NO enforcement.
You are a strong supporter of the Wasaga bike rally. I can assure you if the OPP let everyone do as they please the locals would be screaming for it to shut down within 1 - 2 years. I guess you don't realize that EVERY event of large scale has an increased police presence and enforcement, (breaking news for you... last Sunday, there was a larger police presence during the Santa parade)...lol But then most people tend to NOT break the law, then complain when they are targeted for increased enforcement.
So rather than whine about the enforcement, why not whine to the sport bike riders, who are hooligans on the 400 series highways, run with NO insurance, run with obstructed or NO plates, or hit the rev limiter at EVERY opportunity. If all those activities weren't being done by riders... guess what NO need for increased scrutiny and enforcement. It is akin to those who complain about increased police presence in "their community" yet the next day are complaining that the "cops aren't doing anything" when someone they know gets shot or murdered. Can't have it both ways. Maybe if a certain demographic in the riding community cleaned up their act and those of us who aren't part of that demographic condemned their actions, rather than say well they are being hassled, the scrutiny wouldn't be there? But no it is easier to bash, than deal with the issues.
As for the argument, "well their plate is obstructed your honor, therefore, I can have mine obstructed" is laughable, and you know it. I guess if you ever get a speeding ticket your defence would be well your honor, OTHER people speed, so I am not guilty, because they too weren't charged. GMAFB.