You have to remember that by today's standards even 100kB is not that much. If it's just plain text then yeah, but if it's formatted text with an image as a signature, that can be larger.
In my case, as long as it's text, I don't seem to have too many issues with 50kB, but I do notice a few of my e-mails re-loading when I open them... It just didn't bother me, I guess.