Besides which, if we're going to go with breakability, considering that he last played in the Red and Blue era...
Mewtwo (or even Alakazam) spamming psychic pretty much meant "game over" in that game.
The strategy level in pokemon now has grown a lot, to be fair. The demolishing psychic took in Gold/Silver (introduction of a type immune to it and a type resistant to it), the splitting of special into special attack and special defense, the introduction of abilities in Ruby/Sapphire, the introduction of move slightly less powerful in raw damage but with much higher likelihood of side effects, and the great attack split (where the stat your attack use is now based on the attack itself, not the attack's type) in diamond/pearl have all made the game a great deal more strategic than it used to be. (Well, that and all those stats-worthy multi-type pairing...picking an electric to kill flyers will now backfire badly if you run into a Gliscor, for one)
The introduction of the Very Late Game battles in Black and White (Cynthia especially...there are only two ways to beat her: power-leveling, or fine tuning a team. I went the later part, and it required putting a lot of thought in strategy) had also made strategic thinking a lot more useful than it used to be.
