Passive income (low sec only) moons (POS Mining)

I think there is a fundamental problem with ship balance in EVE online but i could be wrong. But from personal experience, i have been getting owned by frigates when im in a destroyer. It makes me not want to upgrade to a cruiser because then i would just be getting owned by a destroyer? This makes PVP kinda boring? So even if there was more stuff to PVP over, maybe more PVP wont happen due to other issues