Edit: I thought "bishop" was a specifically catholic title. It appears that some televangelists may have misappropriated not just the faith, but also the title.
Anyway, Catholicism is a lot bigger than the Roman Catholic Church. You have other very explicitly Catholic churches such as the Eastern Orthodox Church, and you also have faiths like Anglicanism, which are a weird hybrid where most (Roman) Catholics would consider them protestant, but they refer to themselves internally as a "Holy Catholic church", they have Bishops too (but no Pope, their spiritual head is for historical reasons the Queen of England) and so on.
The thing about religion is that believers try to recruit others and get their standing from that, whether its the small scale parents recruiting their children and deriving authority over their children from that, or those born again who feel compelled to save others. You can't say the same about politics or academia or country music - its not like everyone who goes to university has an interest in educating the unwashed masses; generally, the incentive for someone with a degree is to wish they were rarer! ;)
For what it's worth, my religious beliefs are shall we say pretty individual. I have no reason to protect, support or defend any other religions. I regard many of them to be pretty appalling in a variety of ways and some of them certainly do engage in aggressive proselytising, deceptive practices and such. But not all of them. In general, specific examples aside, the things I have against them have nothing to do with pyramid selling though and lazy opportunistic slurring like this does nobody any favours.