As has been said it does depend largely on context, something that a word filter won't understand.
For example I (and I suspect most of the other mods) have no problem with a female dog being described as a bitch (as that is the right term), when used in the correct context, but I would probably take action if the same word was used indiscriminately or to describe a person (where it's an insult, or just another swear word).
As has already been said, when it comes to the swear filter and harsher swearing people will just (in my experience) try to get round it, and it can/does cause problems for other things at time.
Hence we make it very clear we don't want swearing.
Personally I try not to swear too much in RL*, let alone on forums** where it's going to be semi permanent, as I tend to reserve it for when i'm really annoyed or similar as spur of the moment (rather than the time it takes me to type it in, and reread it)

, and there are far better ways to show annoyance, or emphasise something in the written word if you've got a half decent vocabulary
It's one of my pet hates, how some people will swear constantly and loudly even in public.
As to hosting costs, i'm not going to say how much Spie spends on the forums, or quite what the package has in terms of hardware and support (from what I know).
But I will say you do get what you pay for - and having seen another forum where they relied on one company for hosting and another for backups (presumably to save money), and what happened there, I can very much appreciate how important good hosting is, and why people will spend more on it than the cheapest consumer package.
*About the only time I tend to swear a lot if when i'm in private with friends and we're playing games, where we can't be overheard
**Even on one forum I visit where swearing is allowed it's unusual for me to use more than a very mild one (such as hell)