And there's something wrong with doing that to older members or ones with higher post count? If you made a spam post wouldn't it be fair to lower your post count to 1 as well? How about this, I'll put that rule into play and go back and look at your old posts Poketrainer2004, and I'm sure I'll find some spam posts. And I'll lower your post count. Does that sound fair to you?
Just because you have a post count limit or rules doesn't mean they'll go by them. N00bs gets warnings, and so do older members, same goes for bans. Don't you think older members should know better? You can have a member that's been here for 2 years and still have hacked Pokemon.
And yeah, a post count limit would likely mean spam. You will have people randomly posting around PC just to get the 25 posts, and what does that mean? The Mods will have to work harder to clean up that mess. And when posts do get deleted the count will be lowered, the n00b will start a thread in CQ&F and then this forum will be filled up with pointless "Why am I missing ... off my post count?".
Sounds fun.