I know that hard core conservative supporters think "coalition" is a dirty word, I see no evidence that today in 2014/15 the rest of the population has a problem with parties forming a coalition. In fact I think they rather like the idea of parties working together
Look over to here in the UK to see why Coalition's terrible for trust in politics.
Then again in Australia anytime the "right" forms government it is inevitably "the Coalition" meaning the Liberal and National parties - and no one in Australia seems at all troubled by that.
The main reason the coalition doesn't work in the UK is that its a coalition of unequal partners where the LibDems allow themselves to be pushed around. If they had used their central position to say: "if we don't get this through, we will just switch to Labour", then the balance of power would have been quite different.
An NDP/Liberal coalition with the two parties being of relatively equal size could probably work. The problem is that you will likely get a Liberal landslide and a weak NDP, which is a terrible starting point - with the weaker party on the fringe and the stronger in the center. Most functional coalitions are either between equal partners or a big party in alliance with one or two smaller centrist parties.