I think most people make a division between "Christianity done normally" and "Christianity done well", just like one can make that division for rationality. I agree with you that they should be explicit that they're talking about the stereotype of "standard" Christians instead of "correct" Christians.

Because when you look at "standard" Christians, the "we're all sinners" is generally used as an excuse, not a motivation. "Hey, you can't expect me to be perfect!" Instead of actually improving, you just have to want to improve.

Indeed, I might even separate Christianity done well into "Christian rationalism" or something similar, because the similarities are rather strong.