Lower the bar of 'felony' sufficiently and we will all be disarmed as 'felons'. Further, 'felony' is a measure of the severity of punishment and not of 'crime' and is directed by mere legislators.
I pointed out something similar a few years ago here. I think the goal is to have enough laws on the books so that a person can be stopped at anytime and be found guilty of something. And after you have been convicted of a felony (like you say, the bar is dropping constantly) you will lose your 2nd Amendment rights. And that may be the ultimate goal -- disarmament by other means.