If you want to increase quality of players, force them to play both space and ground pvp and not enter till they gain a sufficient K/D ratio and victory ratio.
Because the amount of players who do elite stfs that are clueless about how to debuff, expose, exploit and even flank and enemy is ridiculous. A group of pvpers can really blitz elites and get each mission done in around 10 minutes. Khit on Ground Elite is especially fast if people know how to fight, the only elite that is faster at the moment is Infected Space. I would say Khit Space is tied in time.
But in all seriousness any restrictions to STF's will more likely cause more frustration and anger than see any benefits. If there was a tutorial mission showing and explaining how to fully debuff and flank and enemy I reckon more people would choose to ignore it than do it.
Now wonder how many people will reply to my post without reading it?