i know this is an unpopular opinion but: jack and maddie are not abusive parents.
they’re not going to be winning parents of the year awards by any means, but they are not abusive. they are involved in both of their children’s lives but know not to push into their privacy. they trust their children to make good decisions and encourage them to pursue their interests even if jack and maddie aren’t interested. they don’t talk down to their kids when they’re arguing and speak to them at an age appropriate level. they aren’t emotionally or verbally abusive - even when danny is being disciplined, they are reasonable. they’re pushy when they’re concerned for his safety, but you can’t blame them when you see how dangerous amity park is.
it’s clear that they made sure that both jazz and danny knew the functions and operations of the lab, the ops center, and the home security system and that both of them knew the safety rules of both. they trusted their children not to abuse the equipment and to follow safety procedures (which danny did not do on multiple occasions).
do they have a violent and harsh approach to ghosts? yes, but ghosts that come through the portal are mostly violent and powerful. they are technically fighting a war - an invasion of poltergeists and mostly alone too. they are working to defend their family and city from a mistake they made. also, have you noticed that a lot of the weapons that they make only weaken and contain ghosts? that they haven’t actually made a single weapon designed to completely destroy a ghost? yes for the most part they have no empathy for ghosts, but they’re not out to destroy them. i do think that they put on a façade that makes them look harsher on ghosts than they really are - if jack hated and distrusted ghosts so much, he wouldn’t have released danny in million dollar ghost.
and yes, both jack and maddie get sucked into their projects, but they make sure their kids know where they are and will stop what they’re doing if jazz or danny need them. the only times they were shown as being completely neglectful is during the christmas flashbacks when they were so wrapped up in their arguments that they forgot their children (but also remember those were told by tucker/ghostwriter who are BOTH dramatic). they have both shown themselves to be more than willing to spend time with their kids and they were excited for it.
the fact that they don’t push into danny’s life when he is obviously wanting privacy isn’t abusive or completely neglectful. they make themselves available to him, spend time with him, and will do things in his best interest. they trust and respect their son and they keep an eye on him. the reason why they know so little about his problems at school are because danny doesn’t reach out to them. they have shown themselves open and willing to protect him, but danny internalizes his problems and refuses to talk to them. jack and maddie do try to have conversations with him and when he gets uncomfortable, they let him leave.
danny also knows all of this and he knows that they’ll love him no matter what (he even said so in bitter reunions and confirmed this in reality trip). there are a lot of reasons why he doesn’t tell his parents about his ghost powers (doesn’t want them worrying, doesn’t want they thinking they half killed him, doesn’t want them to accidentally reveal his identity, etc) and i think it’s the combination of those fears along with the worry that they might be scared of him/hostile towards him that stops danny from talking to them. even if you know something to be true (like your parents loving you unconditionally), there is always room for doubt and danny definitely suffers from that.
so no, i don’t think the fentons are abusive parents and i don’t think it’s right to try and label them as such.