Well, I think it is just stupid and unnecessary. 7 lines is too short to say much of anything. As long as it is within reason, people should be allowed to set their own limits.
I thought about going lower than 7 lines.
A signature is meant to be a brief statement or perhaps display a small image you want to share. NOT to tell your life story!! Do you really need to tell the entire history of the XL and IS and how you dont like it in a paragraph that is shown under EVERY post you make? I honestly dont think so. Long signatures clutter up things, makes reading posts difficult. Long signatures are distracting and are unnecessary IMO.