[squeaky-clean]

You can always switch to notation mode and work out the fingering for yourself, just like you normally would. The programs can also allow you to move notes between strings, and it will shift the tab so the note played is the same, even in alternate tunings, so you can quickly try different positions on the neck. I also know Guitar Pro has a feature where you can enter notation or tabs and it will attempt to work out the best fingering for you. I don't know how well this feature works, though.

If something is tabbed inefficiently, that's a problem with the author of the tabs, not the format. I'd say incorrect tablature is similar to incorrect notation. Just because someone can notate music incorrectly doesn't mean that sheet music is a poor format.

The fact that tabs imply a certain fingering is a larger benefit than an issue. Many riffs are only realistically playable with one specific fingering, and a tab can help you figure this out much more quickly than you could with your ear or notation alone. Especially when it comes to deciphering whether something is using techniques that can produce the same notes, but different sounds or ease of playing. Like sweeping as opposed to tapping, or songs written in alternate tunings.

[TylerE]

Not to mention that the SOUND matters too, depending on the fingering. E.g. A high D played on the (plain) 2nd string sounds different than the same pitch played on the wound 3rd string which sounds different than the wound 4th string played up above the 12th fret, etc.