I was actually just talking about this with my roommate the other day; after over a month of work and wait to get my rare-quality hatchling, and then battling with it a few times, I discovered just how subpar its moveset feels. And honestly, it's not that fantastic of a tank, either. Particularly compared to several others (any crab or turtle comes to mind). It's really disheartening and disappointing, given how much I love the bug/insect pets (...well, most; go away spiders >8C) and the aforementioned effort/annoyance of sandstorms.
I keep thinking how nice it would be if it had, for example, one of the raptor hatchling movesets. They're real beasts (pun intended), and can also take some decent hits.
For now, I'm babying my silithid hatchling to level it to 25, but I sure wouldn't bother if I didn't like its model so much. I may yet relegate it to "looks pretty and is kind of a prestige pet to have" and keep using my team of various striders/snails/humanoids.
tl;dr: yeah, I agree, and wish we had the option to choose from the type's pool of movesets (in this case, beast). Or something.