I love how Labour supporters still think Blair was THE PROBLEM. Something to be distanced from. He made them electable and won two terms in office. Neither Brown, nor Milliband did it. Brown stabbed Blair in the back and he was more old Labour. Red Ed was still further towards old Labour and his entire spiel was about kicking the rich and fighting for working people, but did even worse.
I can only speak as a left-wing voter rather than a Labour supporter (in 3 general elections now, I've twice voted for Lib Dems and once the Labour Party). I want proper, conviction politics of the left to vote for in a serious, national party (I don't really consider the Greens as a viable option at the moment - seem more of a middle-class sect than a serious party, but things could change). Now Labour might win elections more easily by going the Tory/Blair route, but we already have a Tory party to vote for. It don't think it's a good thing for democracy if Labour become solely concerned with winning elections by whoring themselves as Tories with red rosettes. Otherwise it doesn't really matter if the Tories win every single election, because there would be no big choice to make between the parties anyway. We should have a proper choice to make between the big parties, imo.
The Lib Dems tried to sell themselves as being bang in the centre for this election, look where that got them this time. People to the left (like me) abandoned them and people to the right went to the Tories (because why vote for an imitation when you can get the real thing?). Nobody believes in them anymore, it doesn't matter how sensible they want to sound.
The issue, as much as anything, is sincerity and conviction (IMHO). Hence the rise of the SNP and even the millions of votes for UKIP, when you consider where they were 5/10 years ago. There are many, many people who don't vote because they don't believe in anybody. I have to admit, this is the direction I am heading as a voter.