Yeah, Garbodor really stinks. I did evolve my Trubbish, but only for the Pokedex entry. I've often been neglecting him (probably because he has a Bold nature and also has one of the worst abilities ever, Weak Armor) because as you said, that movepool is terrible and it's a bit like Unfezant in that it learns more special than physical attacks and its Attack is higher than Sp. Atk.
And when I train on Route 9, the wild Garbodor can just literally annoy you by either Stockpiling or outspeeding you with Weak Armor.