They might not be pushing you for payments. Now are they? If you are only willing for free support, there are a lot of people of forums which provide free support. If someone helps you off-forums and asks for money then you can come back here.
There is nothing wrong in charging for support. Lets take an example.
You did something which screwed up your site - White screen of death. You are asking on forums. Someone (probably a freelancer developer) respond with the possibility of taking a look at your stuff. But then some other problem creep in, then it would be wrong, to call that person wrong in case he didn't help, offer the option of paid support. You need to understand how much everyone does for free in open-source communities.
Considering this as an another example, someone might approach me for a fix, I will guide them but if they keep stumbling on the same issue because they can't follow instructions, got lost in code etc, then I offer them paid support to do it. There is no point in putting in more & more time when the other person can't follow exactly. On forums its a different thing, you are helping late visitors who came up searching too but on personal level, it all starts to suck.
As a nutshell, there is nothing wrong in paid support. You don't want them, walk out when offered. Its totally justified. Moreover you shouldn't be trusting everyone who wants to get access to your site to fix it. I am just considering all of this as a possible scenario for justification. I am not in favor of what the topic title says at the moment. :)
I hope I made my point clear without leading things to a debate.