You're right, it is better for the kids to have both parents if possible. I can appreciate how hard it must be to have to try and cooperate with someone so misguided.
In our case, when XH took me to court (after not bothering to show up the first time around, and realizing you have to pay child support even if you don't wanna) the Judge asked him to commit to a regular schedule when he could see the kids... he wasn't going to get whatever he asked for, but what was his availability? His answer was that he couldn't answer that. XH's plan was to let me know when he'd be in town and 'meet the kids for coffee'! The reason I left him was that he assaulted our son (he served an 18 month suspended sentence) I was asking for professionally supervised visitation, once or twice a month for about 12 visits, and then to reassess what sort of visitation would be appropriate for them. The judge told him to reapply when he can assure the court he was able to commit to visitation with some sort of predictability, and ordered that a report be done. The report would tell the judge what sort of therapy or anger management XH had taken during his sentence, and what kind of visitation would be appropriate. He has email & phone access now, which he doesn't use... he's sent both kids one email, and responded to one of DD's emails in which there wasn't even a "Hi!" to DS. I could say okay to his drop-in 'plan', but I'd be bypassing the court to do it... and if he ever hurt one of the kids again, I'm pretty sure DCF would blame me as well. Right after the assault I was told that if I went back to him (ha!) the kids would be taken from me, and if the court gives him access please call and let them know about it.