As for disabling sigs completely, I'd say that's exaggerated. A few text lines are sure okay. But I'd also reduce this "maximum allowed space white box". 20 lines of text is also too much. People who need to say THAT much can indeed do so in their profile, and don't need to put that text under every post.
Hmm ... well, the way I tend to see it (based on my very limited experience) is that signatures originated in an environment where, for any given post, all the reader can see is what the author actually put into their post (I'm thinking "e-mail mailing list" here). If the author doesn't add a signature, all the reader gets is a name and a e-mail address. That's pretty sparse. There's very good reason for the author to add a short signature containing e.g. additional contact information.
But on forums like these, the signature is
not the sole source of such info. Every forum post comes automatically with a huge set of information (author, power level, post count, contact info, website, link to profile, etc.) presented in a well-organized, standardized manner. The forum's built-in mechanisms are such that we can quite easily make do without signatures.
So signatures are not a necessity here. They're just an fun extra. But also, at times, an annoying extra.
That's not to say that signatures are "bad"; I do like to look at them from time to time. But when I'm reading a thread, I'm usually reading the posts, not the signatures. So when signatures are displayed after every post, I usually end up seeing them when I'm not interested in them. Disabling signatures frees me of the burden of scrolling past stuff I don't want, and when I
do want to see someone's sig, their profile's just a click away.
All that said, yes, a 2-line sig with minimal images, while IMO unnecessary, is pretty harmless. I approve of that. But once we have people who want to add additional info onto their profiles, we hit technical issues.
If I understand correctly, SMF does not have a separate "profile text" feature; the signature is the only large block of "SMF code" that goes in a profile. One of my ideas behind hiding signatures by default is that then people won't have to worry about keeping them short. If signatures are only visible on profiles, they can be as big as they want and nobody will be bothered by them. The fact that we have large signatures shows that people have a lot to say - hiding signatures by default might be a way to let them do that.
Another option is to let people keep their "extended profiles" on dedicated threads - perhaps members could use their own introductory "New Members" thread for this.
Anyway, not a big deal, just my 2 cents. Hope that was interesting and/or made some sense. BTW I plan on staying with no sig and no avatar, so I won't be affected by any of this.
