Why close threads?

Surfer

Why do some of the moderators close a new thread just because there is another similar old thread on the subject?  I find it extremely annoying especially when you have to trawl through dated garbage which no longer applies!

I stress that when the old post was written, it was probably very relevant but over time it has become outdated garbage.

Please leave new threads to carry on instead of assigning them to another thread which was probably raised a month or more ago.