Monte At Home said:Basically, no. This came up in 3rd Edition design. Twice, actually. And we considered it very strongly. But we ruled it out because we were afraid it would be perceived as a really big change (when in fact it really isn't).
It's easy for me to look at things now and say we should have done it. But considering that the times (and opinions) were different then, I think it's a decision I can still stand behind.
But yeah, I'd be surprised if it survived to another edition.
I think the key issue lies with ability score damage - is there a floor where penalties can't go below? In other words, a creature with a -6 Con is dead (or is it?), but that doesn't easily translate into the flow of the game. It's a lot easier to process that a poison has left me with a Con of 8 and make game decisions based on that, than a negative number with a non-intuitive terminus value.