This logic is absurd. Cops are hands off with bikers not because they own bikes. Extrapolating your logic one could say:
Cops don’t ticket cars because they also own a car
Cops don’t stop people with guns because they also own guns
Cops don’t go after bikers because they factor in if the offense is worth the risk, to both themselves and the public. There’s also a whole thing with outlaw motorcycle gangs that plays into it. Most non entry level bikes can out maneuver and outrun cop cars with ease, yes, even those slow looking Harley’s. Starting a chase over loud pipes would put a lot of innocent people at risk and for what? It isn’t worth it and it’s safe to say if the biker is running modified pipes they are not on an entry level bike.
Story: a buddy of mine had a gsxr 1000 and would purposely screw with cops on the freeway and as soon as they’d light up he’d be gone and doing 200mph within a few seconds, fitting between cars easily. Within 30-60 seconds a bike can be damn near a mile away from a cop car. Radioing ahead won’t help if you don’t know where they went and they were never running a plate to run… most cops know it’s pointless to chase and often immediately call it off. Public safety is more important. Those types of bikers have a way of making the issue go away all on their own eventually. You can’t temp fate that much and not eventually meet yours.