Give Portal experiences Full XP and challenges

I'm not sure how Full XP on portal is considered fair when you know people use it to statpad and obtain ludicrous amounts of exp. This could lead to bots, selling farmed accounts, etc. There are a plethora of other considerations such as match making. How would you try to balance teams if someone had 10,000 kd? It would have made more sense to just lower the requirements for XP needed to level instead of opening a potential loop hole that would be taken advantage of.