That is your opinion (and valid for you), but is not an objective truth.Mods should not have block protection any more than vanilla should. Unless it's a mod specifically for block protection, of course. Or unless you pay extra for it, like IC2's personal chest (which is the only example I know of where you pay extra for block protection).
If I play on a server where others play and we have a lose set of rules (because its a small community for instance), block protection is nice to have.
If I play on a larger server with a no-griefing rule, then block protection is even better. Server rules don't give you back the time spent getting your stuff back (if stolen) or reassembling your setup (if broken/changed). And having been on the internet for as long as I have, I know that imagined anonymity plus the ability to do stuff means that there are a multitude of people out there that will do what they can to annoy others, because they find that fun. Calling back a page, our time is the only truly finite resource we have in MC.
I venture this;
Mods should all have block protection (for their own blocks), unless the mod specifically wants to be 'PVP friendly' (griefer friendly, or whatever you call it as defined by the circumstances) of course. You should never have to pay extra for it, like IC2's personal chest.