Because Cheats are ALWAYS betten then a trainer.
Don't get me wrong - trainers are great for functions a game does not offer - but if there IS a godmode-cheat ingame, it's always the better choice then the trainer. The cheat is wanted and tested, it won't cause glitches, crashes or anything. CH-trainers are great and work in 99% of all cases, but cheats workl in 100% and do not need another programm running. So - cheats are easier (if you can simply enter them, unlike here) and better.
Did anyone read my post?