The issue is not that they are attempting to identify unqualified voters, it is how they are doing so. They are using computer databases that are in some cases several years old and of questionable accuracy. There are reports all over the place of fully-eligible US citizens being identified for removal from the rolls due to this inaccurate process.
This process should be repeated every 8 to 10 years.
BTW, I just got my father off the voter rolls in Georgia. He passed away 3 years ago! I could have requested an absentee ballot for him right off the state website. The effort to remove him was much more involved and required several email exchanges and a couple of phone calls!
Anyway, here is a site you can use to check if your deceased love ones... and others... have been removed. Can I Vote
Verify.