Not to be the devils advocate here, but you have to remember that there are people here on the DIS that are still on dialup. For those people, those signatures take forever to load. The guidelines are set for enjoyment of all.
Imagine that every thread you open takes 40-60 seconds to load, instead of 2-3 on broadband. You still like seeing all the signatures, but you still want to see the threads too. Now if everyone were in line with guidelines, those pages may take 10-15 seconds to load. It makes a HUGE difference.
I don't think people are 'picked on' but I do believe that most of the warnings about signatures go out because someone complains. I'd complain too, if it made that big of a difference for my surfing.
Minnie56, if you want me to make all three of your pictures fit within the guidelines, send me a PM with all of your original pictures and I will get them working for you and still with good quality. I work with pictures all the time and think I can help you.