I have asked 5 questions over a period of many months, and all have been closed/deleted (all unfairly in my opinion) ostensibly by "community" (read moderators).

The last part of this statement is flat out wrong. There has only been one moderator involved in a closing of your question, which was me, and only after the question had 3 non-moderator votes on it. Do not confuse high reputation users with moderators. Anyone with 3,000 reputation can vote to close a question, and these are the users who have been closing your questions. Not moderators.

But my question doesn't solicit debate or opinion. I ask about advantages and disadvantages of different platforms, and my question specifically states

This is exactly what solicits debates and opinions. Imagine if you had asked "Which is better - Coke or Pepsi?". See what I mean?

Isn't that what StackExchange is for? To ask for help from experts?

Yes, it is. But we also expect you to be a professional and this means being able to help yourself.

You have never actually answered anyone elses questions

To be fair, this is mostly part of a boilerplate template. What's more concerning to me is that you have never voted either. You've never given anything back to this community. This is fine if you're providing in other ways - namely good content in questions. You've not been doing this.

My answer was converted to a comment by a moderator.

Because it wasn't really an answer. All you said was "Oh yeah, it can do XYZ! Let me know how you go". That's not an answer. It doesn't tell the user anything they didn't already know. (also for what it's worth that question was terrible as well).

The whole "sales pitch" is "Ask questions". There is no mention of "Go, answer questions".

This is absolutely true. Perhaps we should have that part re-thought in the template we send out.

Is ServerFault just for moderators? Obviously, I'm being dramatic for effect, but the moderators came off as smug, snippy and snobbish, and gave the vibe that they want to keep the site for themselves.

Of course it isn't. But we do hold our users to a higher bar than most of the other SE sites. We expect you to be, and act, like a professional, and we expect you to be able to help yourself as well.

I have asked 5 questions over a period of many months, and all have been closed/deleted (all unfairly in my opinion) ostensibly by "community" (read moderators).

The last part of this statement is flat out wrong. There has only been one moderator involved in a closing of your question, which was me, and only after the question had 3 non-moderator votes on it. Do not confuse high reputation users with moderators. Anyone with 3,000 reputation can vote to close a question, and these are the users who have been closing your questions. Not moderators.

But my question doesn't solicit debate or opinion. I ask about advantages and disadvantages of different platforms, and my question specifically states

This is exactly what solicits debates and opinions. Imagine if you had asked "Which is better - Coke or Pepsi?". See what I mean?

Isn't that what StackExchange is for? To ask for help from experts?

Yes, it is. But we also expect you to be a professional and this means being able to help yourself.

You have never actually answered anyone elses questions

To be fair, this is mostly part of a boilerplate template. What's more concerning to me is that you have never voted either. You've never given anything back to this community. This is fine if you're providing in other ways - namely good content in questions. You've not been doing this.

My answer was converted to a comment by a moderator.

Because it wasn't really an answer. All you said was "Oh yeah, it can do XYZ! Let me know how you go". That's not an answer. It doesn't tell the user anything they didn't already know. (also for what it's worth that question was terrible as well).

The whole "sales pitch" is "Ask questions". There is no mention of "Go, answer questions".

This is absolutely true. Perhaps we should have that part re-thought in the template we send out.

Is ServerFault just for moderators? Obviously, I'm being dramatic for effect, but the moderators came off as smug, snippy and snobbish, and gave the vibe that they want to keep the site for themselves.

Of course it isn't. But we do hold our users to a higher bar than most of the other SE sites. We expect you to be, and act, like a professional, and we expect you to be able to help yourself as well.