I love this game, but i think Gym battles are unfair for the Gym members. The battles should be fair for both sides, if my Gym only has 1 Pokemon its fair that i can only be attacked by 1 Pokemon. Whats the point of having a Pokemon with 2000CP if i can lose with another trainer that has 6 Pokemon with 800CP each. It Should be like the Anime, if the Gym has 2 Pokemons, you as a trainer can fight it with only 2 Pokemons, if it has 5, you can fight it with 5. 

What do you guys think? 

The video games, which is what this GAME is mostly based on, not the anime, also allow the use of all of your pokemon when fighting a gym battle. It is just how it is played, not a problem whatsoever for me, it's to be expected : )

It's easier for newer players to take down gyms this way, so that everyone can have the chance to be a gym leader and earn coins...

Sure but you can be a Gym leader by joining one of your own team.

Exactly, but if you take a look, the main series games area easy because of the same reason. 

you have to think about the people who live in small cities, for example as far as I know in my town there are only 2 gyms, if two or even just one team monopolizes said gym the players who chose another team will have no way to collect coins other than Pokéstops (where I still haven't found any Pokédollars for example...)

In my town the first gyms is 45min away, and first pokestops 20min away, i just desinstalled the game :p

Its a game, someone has to lose. This game in particular is not PTW, plus making 10 or 20 coins at day is not going to make a difference 

This is one of the reasons, drive or walk that far to win over a gym so 5 minutes later its taken by a Pokemon with 500CP -_-

Well, I think you can have up to 8 pokemon in a gym, but you just have to raise its prestige up by training it. I've seen gyms with a lot of OP pokemon chilling in it. If you're gonna do that though, you're gonna need a lot of friends on the same team, or meet a lot of people in your team and train together. Hopefully you can find allies when you decide to take on a gym.