My dad keeps saying I'm creating kids that are too soft

I have 3 kids. My dad is a hard ass. His parenting has always been about making us "tough". Especially my brothers. My dad has the mindset that back in his day he struggled so we all have to struggle too. He kicked both my brothers out when they turned 18 because tough love or whatever. But both my brothers are in jail so take that how you will. My dad has issues with how I parent and thinks I coddle and "feminize" my son. My son is just finishing his freshman year in high school and he hasn't had a good year. My son is in therapy for trauma that happened when he lived with his dad. My ex's dad sexually abused my ex and my ex never told me that so I was allowing a predator around our children and had no idea. Some things happened while he was in my ex's custody and when he was removed from my ex's custody my ex died a few weeks later. It was hard. This happened the summer before freshman year. So it was hard. My son's grades were not great. He was getting into fights. My dad was constantly saying "Back in my dad he would have gotten a switch to the ass!" Constantly getting on my ass about my parenting. My dad's excuse is always "I'm old school!" When I put him in therapy my dad was like "My generation survived without therapy. For years we survived without therapy and now we just throw our kids into therapy. They're fucking snowflakes." My dad knows he has trauma and my dad's excuse is everyone has trauma and back in his day they didn't see a therapist for trauma. They kept it pushing. His therapist gifted him this cat squishmellow and he takes it to therapy and now more public to help keep him grounded. My dad yesterday told him he looks ridiculous carrying that around at his age and told me to stop letting the therapist feminize his grandson. He annoys me so much. I am so close to going no contact but I don't want to use my kids as a weapon and be that person that is like "Well you pissed me off so you lose access to my kids. " My mom loves my kids and cutting my dad off would also mean she would see the kids less. I'm just tired of my dad always saying things and acting like I need to do things his way.