Firstly I wouldn't take his word for why he doesn't have contact.
It always seems that they blame the DCs' mother and sometimes even the DCs themselves, doesn't it?
Even if the DCs have actually been 'turned against' or stopped from seeing the father, I would want to know why, because it seems likely to me that it could be for good reason. I would question whether there had been domestic abuse, drug or alcohol abuse, letting the DCs down a lot, or something similar.
I know there are cases of - to use the new chestnut of the moment - parental alienation, but I think it's rare.
Maintenance not being paid reliably and at a fair rate, whether there was contact or not, would also be a definite no-no to me. Often you see men paying nothing, or the minimum, having a good standard of living with a second or even third family or as a born again bachelor, and leaving their exW and DCs to struggle.
I also would not want to be with a man who speaks with bitterness or hatred about the mother (or mothers!) of his children.
So no, if I was in a situation where I was looking to date or start a new relationship, I definitely wouldn't be interested in that sort of man. That's the sort of man I look down on and couldn't trust.