Sometimes a post in an old thread triggers me to read it. Mnay times I doscover a thread I never seen before! And there is nothing wrong to put a nice reply in a thread when you like it. The few seconds to read the two-word com is for me no big deal. So I don't agree this time with you.
I think it is better to continue a thread better than start a new one with the same subject. On the other hand, the 15 seconds of fame starting a new thread is important too.
