This is only true if you are broadcasting something like digital TV back to earth. There is plenty of physical room in geosynchronous orbit. The spacing is to assure that a receiving antenna can be pointed at the correct satelite. A "silent" satelite can be parked there with no problem.
The stability issue is a reasonable objection. Actuallyt any high orbit will be maintained for significantly longer than a low one. If we can predict 10,000 years until orbital decay brings it back to earth we can presume that either:
1. Mankind will be better able to deal with the problem then, or
2. Civilization will have sunk to a point where the crash won't be meaningful.
Unless yer the poor sap that happens to have his mud and straw hut in the designated landing zone...lol.