It is common. Wisconsin isn't the first state and lots of red states push these methods. To fix this problem, they could send out mailers to everyone, and inform them of their voting registration status, a couple months before registration deadlines, and after the purges. But red states don't want to fix something they feel they benefit from.
Now how much this affects elections is unknown, to the best of my knowledge. I don't recall reading about tens of thousands of people that were kept from voting because of these restrictions. Yes, one person is too many and that is why we need a failsafe, but this hasn't seemed to be a problem for statewide voting.