Walter, I agree with you. Practicing over and over without specific guidance, even if injury is avoided, only adds to tension and fear. And many newbies do end up with shoulder separations (AC joint at top of shoulder) from landing on it.
There is another recent thread talking about alternate paths to rolling and citing Ellis Amdur's method - worth searching for. His DVD is well worth the price.
Yes... Practice makes permanent. "perfect" practice makes "perfect", permanently..
A bit of an exaggeration but the school of hard knocks has a high failure rate.