Pretty safe to assume we all on here have moderate to strong geek tendencies.
We love lists. Lists are a good.
They are also useful to see which are the most popular cards.
If you are interested in a particular card you can look at the list and ask someone with one about it.
I find it useful for the benching threads as sometimes people put "stock" as their clockspeeds and it can be difficult working out what that means if you don't know which brand of card.
The company reps find them interesting for obvious reasons.
There are probably all sorts of other reasons too.