The non-commie left really started to dust itself off in 1974 with the rallying of most of the PSU to Mitterrand's PS but only after 6 years of complete utter chaos. Already, the same dynamic as today and as in 2002 between the non-commie extreme left and the PS.
So yes, it did take time in those years to pull what is now the PS together (and maybe now not so together...) My memory is still, though, of an ongoing movement with its thrust and logic (if you were for elections, not revolutions), and not of total chaos. I don't feel that kind of upward movement today...
Perhaps that's why it's less the extreme left (commie or not, today, it doesn't matter) that bothers me as the lack of focus and thrust of the PS. The fact is it's easy to imagine no party discipline behind whichever candidate is chosen. And that, of course, would facilitate a hopelessly split vote in the first round, and a Le Pen/Sarkozy second round.
Jérôme's point seems solid to me, though : that the voters on the left might inject some discipline after the 2002 experience...
