@unforth-ninawaters replied to your post

I can see him being rough with them – after all, he’s rough with them when he shows up in S1…

Yup! 

Like, what blows me away is when I see things like “if you think John was a bad dad you probably didn’t watch the first two seasons” and I’m like…. no I watched the first two seasons. I watched John use one of his sons as bait, blame his other son for not killing the monster, almost get in a fist fight with one of his sons, be rough with both of them, ignore Dean’s tearful and worried phone calls, ignore the fact that one of his sons ALMOST FUCKING DIED, and yelled at one of his kids for not killing him. 

A+. Dad of the year material, right there.