I've stated in the rules why this rule applies - it stops a user with one post coming on, requesting, then never to be seen again. A member with 250+ posts seems to be an 'active' member, which means coming on here a lot and posting, and crediting, and helping etc. This also gives us time to make kits for the more active.
If you don't like the rules, go to another request thread. It's totally fine by me.