Almost everyone is welcome, apart from spammers, scammers and dickheads.
No one "owns" a thread. It's a community discussion. Out of many thousands of active members, not everyone is going to get along with everyone. If you have an issue with someone and you feel you need to take it up with them, use the PM function, otherwise, consider everyone else reading these threads.
Please try not to get into pissing contests. This isn't aimed at anyone in particular, but offered as general advice.
Also note: I'm cranky this week, tolerance for nonsense is low. Consider this forewarning.