I think OP's point about the 'spicy takeaway curry after waiting an hour past their bedtime for it' is that it illustrates the wider point about her Ex being incapable of putting the children's needs first, of caring for them properly, of parenting.
Of course there's nothing inherently wrong about a takeaway curry for a two year old. Our one loves it. Do I make ours wait an hour after bedtime before I can be bothered to get it in, because I'm thinking of myself and when I want the curry rather than being aware that a two year old needs feeding at x time if they've had lunch at y and need to go to bed soon? Of course not. Do I make sure said curry is something they like, is not e.g. too spicy, too rich, something they won't eat? Of course I would (OP's implication is that the 'spicy' curry isn't something they'd like).
It's all part of a bigger picture of neglect at all levels, isn't it? Not watching. Not feeding. Not thinking of what they need and caring, nurturing. Not loving them, even - oh yes it's easy to say it - 'aww of course he loves 'em!' - but it's not true - a man who makes a four year old childmind a baby and then shouts if they can't do that impossible task doesn't love that four year old. A man who shouts at a baby for wetting itself doesn't love that baby. A parent who doesn't watch, who doesn't care, who can't see what the problem is is a DANGER to a child.
It's low level incapability, neglect, lack of care... right up to when it gets serious, when you have a baby not being supervised because its carer is glued to the laptop. Would you want your two year old in that situation? I wouldn't.
OP is doing the right thing. Absolutely there's no need to be confrontational. OP is aware that contact should be maintained and will hopefully look for ways to do that safely, and presumably that's what will be suggested, amicably and fairly. But there IS a need to be firm - to say - you cannot look after them adequately and I am not prepared, as the other parent, to not protect them from potential harm.