Well, their Pokémon are weak because they only used Rare Candies, and didn't EV Train. If they were just a bit smart, they would use AR to change the IVs of their Pokémon to 31.
Anyway, I'm against cheating on Pokémon. This is mainly because you spend days, months trying to get a good Pokémon from an egg, spend more hours doing EV training and checking its IVs, while people can get Top Pokémon in a couple of minutes.
Another thing I'm against to is cloning in Diamond & Pearl. This takes the unique abilities of a Pokémon in order to get better ones. Unfortunately, I did cloning in the past to get events, as there was no other way to get them unless trading in the WFC. But I don't do it anymore and I disapprove whoever does it.
"so what if i cheat, the more fun i have :D"
I disagree. Cheating causes the time spent on playing so much it becomes boring to cheat...
"I have 63 level 100 legit pokemon, all trained up. The only 'cheat' is that I trade them from one game to another so that they get boosted experience points - but that's a legitimate tactic."
Yep, trading to another game and training is the best method of getting to Lv. 100, for instance, battling the firsherman in Route 222 with another trainer's Pokémon will cause you to get 10,000 exp points in just one battle. That's quite a fair method to train Pokémon.
Well, in the end, cheating in Pokémon is bad, really bad...