Maybe this thought has been shared about gyms but...
How about only allowing 7 consecutive days for each person in a gym? It would get cleaned out, or at least a couple of spots open every day. It makes everyone play their way back in, and makes things a little more interesting and maybe fun.
Answers
So the person in 10th spot needs to maintain the gym for everyone else, while the person in number 1 spot doesn't need to do anything to maintain their spot.
Doesn't this just magnify the problem with CP determining gym placement?
I don't have a better solution, but this doesn't appear to be a good one to me.
The problem with CP is a separate issue of who is in first or last. This mechanic is about what happens to the guy in last. If you’re the first guy to fall off the list it is up to you to stay there. If you don’t want the spot another trainer can take it. Other trainers in the gym would care as open slots would have the possibility to bump them down if a higher CP mon is placed.
No...you don't get to be a high level player by attacking gyms.
Spending your PoGo playing time doing gyms is the least efficient way to gain levels in the game.
If the game forces low level players to continually attack gyms to be able to keep a mon in a gym, then the gap between the high level player and low level player will continually grow.
The low level will be spending their play time ensuring continued coins for the high level, while the high level is free to grind catches to gain even more XP, while a lower level ensures they can keep their gym spot.
Do we really want to discourage lower level players from taking part in gyms altogether?
Please don't take my discussion of the idea personally. My reasoning is to discuss possible gym mechanics, and how specific changes might affect the game itself.- I am not doing it to upset you.
Maybe up capacity to 15 so you can enter? But seriously.. I see everyday as a hard fight. I have currently 1 gym for 2-3 weeks and 1 for 2 and other 4 weeks that has been taken down by spoofers (dunno why it took them so long).. then the rest is an everyday fight unless it's 10 and no other enemy lives near gym radius and can attack from his home.
Mystic suburban area, gyms stay blue and level 10 for weeks - even Instinct gyms last for days despite not being fully prestiged. Seems to me the drop-off player rate is accelerating again. Really wouldn't be in Niantic's interest to "expire" gym defenders because would expose the lower player base. Also it is to Niantic's interest if inactive players are sitting in gyms taking up spots and making at least some players pay real money for coins...
The reason is I live in a town with nine gyms, all valor, and the only thing that's changed in two months is that someone with two accounts kicks someone out once in a while to get a friend's in. I could take the gyms down here and there, like I did at Christmas, but I'd rather grind stardust. I do have pokemon in gyms out of town lasting over a week, so I'd be affected with my suggestion as well.
A day limit would be torture spoofers have enough of an advantage already, this would benefit them as it would be much easier to get back in a gym from a computer then to actually show up. The fact that my Pokémon can compete in the gym scene and stay in gyms steadily is what makes the game fun, but if I had to attempt to get 10 gyms each week that would be torture.