I’ve always thought that issuing free passes to all appropriate taxpayers/residents would be a great way to go. Then you can raise the non pass price to soak those tourists!
They're there! AC Transit runs a program called Clipper Start. The problem is, low income folks just don't take advantage of it, and it's (without further study) unclear why. This was identified during the session on fare enforcement and exactly as you say, there's interest in promoting it more heavily and trying to jack up the price on tourists or high-income leisure riders.