When my signature doesn't match on a check, the bank calls me to verify I actually signed it. Well over a billion checks were written in the US last year alone -- we can't verify signatures on a far smaller number of ballots?
In any case, I'm not wed to signature matching. What other form of verification would you suggest? The current situation of "no security whatsoever" isn't workable, plain and simple. It wasn't a serious issue when a tiny fraction of votes were mailed in, but in this election the majority were absentee ballots -- the first such ever in US history.