You really can't blame them. The recount movement is aimed at ousting Donald Trump and achieving a victory for Hillary Clinton, not highlighting voter fraud.
A few individuals are trying to bring voter fraud to light.
Hans von Spakovsky is one. See Hans Von Spakovsky: ‘We Know for a Fact There Are Non-Citizens Registered and Voting All Over the Country’. To wit:
“But anybody who thinks there aren’t organized efforts, just take a look at that undercover video that Project Veritas released, where you had two Democratic campaign consultants saying, ‘Oh, yeah, we’ve been committing fraud in prior elections. We’re going to do it again in this election.’ And how do they do it? They organize groups of people and either bus them or send them in private cars into states to vote where they’re, of course, not supposed to be voting. How are they going to do that? They use the names on the voter registration list of people who have died, who’ve moved away, and false names fraudulently registered,” von Spakovsky continued.
John Fund is another. See his 2014 article, Undercover agents were able to vote as dead people, but election officials are attacking the agents. Excerpt:
Liberals who oppose ballot-security measures claim that there are few prosecutions for voter fraud, which they take to mean that fraud doesn’t happen. But as the New York DOI report demonstrates, it is comically easy, given the sloppy-voter registration records often kept in America, to commit voter fraud in person. (A 2012 study by the Pew Research Center found that nationwide, at least 1.8 million deceased voters are still registered to vote.) And unless someone confesses, in-person voter fraud is very difficult to detect — or stop. New York’s Gothamist news service reported last September that four poll workers in Brooklyn reported they believed people were trying to vote in the name of other registered voters. Police officers observed the problems but did nothing because voter fraud isn’t under the police department’s purview.
Finally, John Lott provides a list of voter registration abuses in It’s Delusional To Think That Voter Fraud Doesn’t Exist.
Most of us think of Democrats when we think of voter fraud, and if that's a realistic assessment, it's little wonder that Democrats work so hard at ignoring the problem.