Originally Posted by Ranger
...TElling people to leave them of mountain bikes is horrible advice. Both instances were on mountain bikes for me and I don't even ride hard. I don't trail ride, do jumps or any of that stuff. ..
I disagree. He's obviously not as sophisticted as you are and the plastic disc is there for just such a person. You may have had a bad experience, but for the overall majority of new bike owners, the disc does the job, hence placed there by the manufacturer.
I don't use/like the disc, but I can't assume that everyone can adjust their gears and build a wheel from scratch either.