Agreed about the approach, but I too - like many regular helpers here (time given freely, putting up with jibes here and there) sometimes get frustrated. Sometimes. Not enough coffee, too tired, frustrated because helping in another thread is taking too long and we snap a bit. Just like life. It's not pretty but it happens - and the medium of text is appallingly bad for carrying meaning and context.
If someone regularly posted snidely, had a pop at people then I would email them about it, I could block them from the forum for a space of time. I have done both. But for a regular person here to snap a bit, I cut some slack - wouldn't you ? Note: 'some' - not all :)
I agree to a point, but the majority of time people aren't daft enough to resurrect these posts, and certainly not as many in such a short space of time.
Closing threads is answer in part - though there are a LOT of threads, so I prefer to do that only in circumstances that are more appropriate.
And old versions - I run a 1.2.2 blog, I know people with b2 blogs so leaving threads open to them can be helpful should they ever post.
It is difficult striking a balance here - and sometimes we get it wrong. All of us do, but hopefully that brief moment of wrong can be mitigated by the more plentiful moments of advice and support :)