In the words of an ATC Supervisor and fellow Trainer, Aquila, solve the puzzle of working in general aviation traffic. Don’t deny due to traffic volume.
It’s a very rewarding way to go about controlling. Stated in 7.1.6 of the ATC Manual:
No Light Aircraft – This command must be specifically reserved for large hub airports (such as EGLL, OMDB and VHHH) where it is not appropriate to have light aircraft. In addition, their presence would cause undue delay to all other aircraft types due to the aircraft characteristics. Controllers should note that this is not traffic dependant, a consistent message must be sent that there are other, more appropriate airports for light aircraft.
Repeat. This command must be specifically reserved for large hubs. X airport may be busy, but if there’s a gate I’m allowing them in. It’s a measure of your skill as a controller. If you can’t handle it then maybe busy airports aren’t the smartest idea.
For pilots, we always will need to accommodate traffic. It’s just as unfair to the B737 pilot that needs to extend a few more nautical miles as it is to the C172 pilot who gets denied entry into the airport.