may be missing something
The actual drawbacks to Corruptions (Utility skills which apply conditions) are often much less than they appear, especially when you combo them with other Necro Abilities. Skills like dagger 4, staff 4, consume conditions, plague signet and well of power are waiting to throw those conditions back at your enemies, or to empower you with them.
Even without one of those skills available, I’d say that epidemic and corrosive poison cloud are still pretty safe to use. Three stacks of vulnerability barely matters, and the 6 seconds of weakness is acceptable if you’re willing to give up damage.
As to whether or not a necromancer is what you’re actually wanting to play: only you can answer that. I’d say that you’ll only find more skills you actually like as you continue though.
It’s pretty obvious, and nobody’s impressed.