I would argue that, no, it's not. So long as the question being discussed is a matter of RAW, then experience is not a valid argument. If someone has played a game for 20 years, then yes, they're likely to know an answer to most questions involving the rules.
However, if someone challenges them on one of those answers, why does 'I've been playing this game for longer than you have' become a valid argument? Shouldn't they still have to site their sources?
This forum seems to put a lot of emphasis on citing your sources, and I'm wondering if experience should really be allowed to be one of them, when the question at hand is a matter of RAW. After all, just because you've been playing a game for twenty years, if you've been playing it wrong the whole time then you're still playing it wrong.
The specific reason I brought this up is because of something that happened to me while I was gaming. I said that I drew my weapon as I charged, and another player at the table said you couldn't do that. I knew that he was wrong, and said as much. His only argument to this (which everyone seemed to go along with, for some reason) was "I've been gaming for 20 years. I know what I'm talking about." Well, surprise, surprise, when we looked up the rule (correction, when I looked up the rule, at the end of the session) in the game we were playing, it was allowed. I pointed this out, and that's how we've played from then on.
Why do I think this is an issue? Well, partly because, when I ask a question that concerns RAW, and I get back an answer that doesn't quote where the rule came from, it's less helpful, as I now simply know that said rule exists.
What does that matter for this forum? Well, mainly, I just don't think that citing your sources in matters of RAW is strongly enough emphasized here. When I first asked this question the answer I got back did not include a source. When I asked for one, the first thing I got back was a link to another question, also not stating its source.
Now, I admit, it could simply have been an issue with that specific question. It could be, that, had I asked any other question that concerns the RAW, I would have gotten back an answer with a quoted source, or at least been given one had I asked. That said, I brought this up in the first place with the hopes of discussing the issue, to determine if it's an issue at all, which is why I tagged it under 'discussion'. It was late when I wrote the question, and I forgot to add the 'does anyone else think this is an issue?' bit. For that, I'm sorry. I'm not trying to rant, or be argumentative, I just want to help make this site as helpful to people as possible. And, as I've said, in my experience, answers concerning RAW are more helpful when they cite a source.