Please read the terms of service, PTA, they have been updated. If you want an explanation though, it is because these are meant be be "endgame" gyms per se, another activity to do. We are not a competitive battling community, and the restrictions are made to make battles and teams more balanced as we all know not all types are created equally. As well as balance, the restrictions hold true to the official Pokemon games gym roster pattern-- most gyms do not have all OU teams stacked with EQ and subpunchers and walls. Honestly, I find competitive battling to be extremely pigeonholed.
Also, youmay have TWO wildcard Pokemon, as long as you have 4 other Pokemon that fit the gym type. "Wild card" Pokemon MUST fit the theme of your gym. For example, if your gym theme is desert then you can have a Cacturne on your ground type team as well as one other "wild card" that fits your theme.
Also, youmay have TWO wildcard Pokemon, as long as you have 4 other Pokemon that fit the gym type. "Wild card" Pokemon MUST fit the theme of your gym. For example, if your gym theme is desert then you can have a Cacturne on your ground type team as well as one other "wild card" that fits your theme.