Kevin Drum defends it:
Thirty years ago, voting for individuals wasn't crazy. There were conservative Democrats and liberalish Republicans, and they sometimes helped the parties make deals in Congress that, perhaps, made the independent-minded folks happy. Nothing wrong with that.
But no longer.
We have, for all practical purposes, a parliamentary system these days, with strong party discipline and down-the-line voting. Almost no one crosses the aisle to vote for compromise measures anymore, and this means that it make a lot less sense to vote for personalities than it used to. Here in California, even some loyal Democrats might think that Barbara Boxer is not the greatest senator in the history of the Golden State, but so what? Given the current state of American politics, all that matters is that she'll vote for the Democratic agenda and Carly Fiorina will vote for the Republican one. That is all ye know, and and all ye need to know.
As he acknowledges, the argument only applies to Congressional races. "For statewide offices like governor, insurance commissioner, attorney general, and so forth, voting for individuals makes a little more sense."