The Bishop: No longer needed?

So I saw a very interesting argument today regarding the Bishop class.

"Let's be brutally honest here bishop class has been reduced to a minimal role when it comes to bossing. Bishops are used for leeching and the only other use for them is door and res or hs mule. You will almost never see a mage being the main attacker in a boss run other then maybe a 1st gen run in a new server where the majority of the people made a mage class. At boss they will always be just a support class, and are pretty much not needed anyway. Must suck to be replaced by a pet equip and all cures. If it wasnt for the fact that they are needed in gpq and cwkpq, you probably could do without a mage class period. But then people would actually have to train instead of leeching. xd"

So what are your opinions? Are Bishops truly no longer needed for Bossing? Do you agree/disagree with the above paragraph? If so why?

Judging from this Bishops are only used for:

- Leeching
- Door
- Res
- HS
- Be a support class
- Needed in GPQ
- Needed in CwkPQ

Well, that surely doesn't seem like alot of things.