[midgetjones]

I agree, I just feel like it ends up as a crutch for a lot of musicians. For example, it isn't very specific in terms of rhythm so you get a lot of beginners who see that part of music as loose or unimportant.

But of course, up to a point, lowering barriers is always a good thing for beginners.

[squeaky-clean]

Depending on the style of tablature used, you can convey rhythm, and more. I'd say it can actually get more specific than staff notation when you allow for guitar specific notation, like all the different types of legato capable, harmonics, and specifying which string to play a note one (it makes a subtle difference).

Here's a screenshot I took of a random song in TuxGuitar (a GNU licensed tablature editor/viewer). You can see the rhythm fairly clearly, as well as the difference between pull-offs and slides.

http://i.imgur.com/bg9MitN.png