As the saying goes the only good backup is a restored backup - the rest is unknown....
The reason to reduce the number of restore points is so that you do not overwrite a good backup with the currently misbehaving system you have.
A restore point of yesterdays virus infecteded system is little better than todays virus infected system - so the best advice is to make sure that you can restore what has changed from your last restore point but be positive that the last restore point you have is clean and valid.
It goes back to the reasons why you have the acenstral backup... I wont explain here (if you dont know of it - but its documented) as its near 5am and need to be up soon but - it gives you fall backs on should your most recent backups be corrupted.
The biggest problem with performing a backup/restorepoint is that you are backingup and then restoring the very same problem you are trying to fix.