Rather rude response I'd say.
Every transaction is individual. When someone adds something to indicate they are firm on the price or they have their head in the clouds or are unwilling to even talk....I don't bother them unless I'm willing to pay their price.
I also don't buy and sell very often at all. However, every "lowball" offer I've ever made has been accepted.
I don't think it's rude (I'm in there too man) I think it's funny. And just like you, I don't buy and sell a lot but I have had every single "low ball" offer accepted.