In the end it's music. It's all about feel! Would anyone of us artists like music if it wasn't for the feel of it?
So just because someone can't play to a click does that make them worthless? No, not if in the end they add the right feel to the music. If someone can't play to a click I stress that is a very important thing for them to work on. It should be part of their daily practice. But I don't tell them to sell their instruments and give music up, or comit harakiri because they are dishonoring the rest of us who can play with a click.
The point being every situation has it's own solution. Not just different people but different songs. Sometimes a wood-block click, sometimes a hi-hat click, sometime a loop, sometimes no click at all. Different note durations work for different songs and music styles. I've even started with a click and muted it after several measures. There is a reason we have all these options in Sonar...
And yes, when playing right on time with a click, the click sound will dissapear at any points a drum is supposed to fall perfectly on the beat. Musicians that have excellent internal time actually seem to be keeping time for the click. Like anything else, it takes practice.