It's not that the signatures are causing the site to crash - they aren't. The site has plenty of resources.
It's mainly that the signatures have gone uncontrolled since day 1. It's been time to throw the rules in there for several years. In the past, it was just done off the "common sense" rule, and the blatant abuse rule. Unfortunately, we got to a point where we needed to draw a line in the sand and actually have real rules on it.
There is still plenty of room for a signature, yet it's not overly long to take up a ton of room on each page. Users won't need to scroll half way down a page just for signatures.