The short answer is that it's a very useful card, albeit one that should have never been printed. The longer answer is that it's primarily used to pull a weak Pokemon into the active spot for an easy knockout, such as an unevolved basic or a damaged Pokemon that retreated during your opponent's last turn. It can also be a stall tacting, forcing out a Pokemon with a high retreat cost and no energy attached. It's easy to see why nearly all competitive decks run four copies of this card. Honestly I find it a little too cheap in the current metagame, but it's practically needed to win.
Catcher's effect is exactly the same as the Base Set card Gust of Wind, which isn't nearly as infamous despite being a common not an uncommon. GoW existed in a format where attacks usually did lower damage than they do today (three energy for 40 damage used to be good), making early game OHKOs less common. Pokemon EX also hadn't been introduced yet, so the only way to take multiple prizes in a turn was to inflict bench damage.