The problem in 2009-2010 was forced demobilization, not idealism.
There is no evidence at all that we'd have got more things done if only we'd proposed nothing but small increments.
The trouble was that the activists and idealists were ordered to shut up and go away, to do nothing to try and mobilize public support for the Obama proposals.
And then, in the summer of 2010, the party basically announced that the midterms were already lost, made no effort to defend the administration's achievements, left the entire right-wing attack on the administration totally unchallenged, and made no effort to put together any effective campaign to get the base to the polls.
So it's bullshit to blame anything on the proposals being too ambitous and the administration posture towards Congress not being sufficiently capitulationist and cynical. Nothing to the right of any administration proposals would have done any better in that Congress, nor would they have been more receptive if the administration had only been more dismissive of activists and activism.