Hard to be sympathetic to the willfully ignorant.
What about all those who want to vote but aren’t citizens?
As for me, I'll go with the Reasonable Person argument instead. Would a reasonable person expect that to vote in April, you must be registered by last October? No he would not expect that. Therefore, I am sympathetic to the iced-out voters here.
Notice that I'm not saying I'd excuse their mistake, but yes, I'd be very sympathetic.