There really is no need to be so testy with this. It was a simple enough suggestion, and a practice that is followed by most other developers across many different pieces of software.
Having tight beta expiration time frames also puts unnecessary pressure on releasing the next beta, possibly before it otherwise would have. I agree releases should happen when they're stable, so that's the right thing to do - what I'm suggesting would allow you to do that better.
And it would also get pesky users like me off your back, hey
You could've just said "Thanks for the suggestion, we'll take it under consideration" and then do nothing if that's what you felt like.