I’ll list some scenarios below.
Casual Server: Okay, CS doesn’t have any ATC, as it is disabled. If you wanted to have realism in the CS, head on over the TS, it may be a bit better than the CS. When I sometimes join the CS for some fun flying, I don’t usually see people use UNICOM, or UNICOM correctly.
Training Server: Only EGLL, KLAX are always controlled. With that split second when the user disconnects, you may be transferred to UNICOM. You could just wait maybe 30 seconds, and someone else would start controlling. I barely see smaller airports with high traffic in TS.
Expert Server: ES only controls airports in the schedule. That’s why when you look at the inbound aircraft, certain airports have 100+ inbounds sometimes. Most of the time, these airports (busy ones, hubs, etc…) will always/IFATC will always try to have these controlled. As I see, there are still flights from other airports to the HUB of the day, but usually, that doesn’t mean there is a lot of traffic at the airport. Very uncommon to see a high amount of traffic in a airport that is not part of the schedule.
All in all, this isn’t a bad request, it just is not practical for the time being.
Thanks for reading,