Well, yeah, Paladin. I never said that the co-pay shouldn't be based upon the person's income/ability to pay. I'm fine with it being graduated like that.
No-cost doctor visits for everyone is a bad idea all-around, since it dramatically increases the cost of doctor's visits by making people go in when they don't need it and making the doctor's order tests that they really shouldn't, etc.
In any case, your problem with catastrophic coverage boils basically down to 'that's how it already works!' - the poor already skip on going to the doctor and wait until problems are serious enough to go to the emergency room, and the emergency room is required to take you in. Also, catastrophic situations are the ones that are the most significant cost, and can be pretty likely to completely bankrupt a family - thus, not providing catastrophic coverage means we'll wind up with more medical bankruptcies, etc.
And note I never said anything about there not being a deductible or co-pay with the catastrophic coverage. If that deductible is something like $1000, it's pretty high, which means people are going to want to go to the (much cheaper) doctor in order to get preventative care, while it's low enough that it won't bankrupt almost anyone.