Persistent penalties to attack rolls are a pain in the abbacus since they have such massive impact on game balance. Penalties to attack rolls are about the worst thing you can do to your players because it is the most vulnerable spot of their characters in terms of performance. Cut their attack bomus and watch them die in a L+1 encounter because of lack of control and lack of damage.
This is actually false. It's not a massive impact at all.
I played for more than two decades, all of the way up to 3.5 with either:
1) -1 to all D20 rolls at half damaged, -2 at zero or below (for those PCs that could still fight below 0), or
2) -1 to all D20 rolls at one third damaged, -2 to all D20 rolls at two thirds damaged, -3 at zero or below
depending on the campaign.
It does force PCs to go to the well a bit more, but even at -2 when seriously hurt, the death spiral syndrome that people talk about is exaggerated.
People who haven't actually played in such a campaign really don't get it that missing 1 time in 20 (or even 1 in 10) where the PC would have hit is more of a psychological effect on the player (influencing actions) than it significantly affects combat.