No. If users really want to delete their system restore points, well, it's not Defraggler's problem.
A lot of people seem to think it is safe to delete restore points since they are "useless" and use a lot of space. That's wrong.
I don't think Piriform wants users complaining about how they had a bug and can't restore their system since Defraggler deleted the restore points.
For the "lite CCleaner" idea, I think it would be better, in the cleanup prompt, to show a link to CCleaner.com and say it will remove junk even better.