I don't think that the postcount /-rank matters (at least not for me). I think it is more that they try to make one's name.
I think the most important part is the content of a message. If it is pure fan-boy-ism like 'OMFG, THIS ROXX' or the opposite 'BHAA, THIS SUKS' then of course one lines should be deleted. But even if there is a long message (a few hundred words) and the content is like the afore mentioned, then it should be deleted as well, wheather it took time to create the message.
The other way round: if a short message contains every aspect like a longer, but not that well phrased message, why should it be deleted? Maybe the emssage sounds a bit harsh, but if the content is the same (and it is possible to get it) why should this be a bad habit? My mother tongue is german and I haven't got many experience in talking english, thus my answers may be phrased more complicated then needed. Maybe a native speaker could formulate it in one sentence where others need a dozen?
Uhm.. I hope I didn't got anything wrong
