No one lives in your shoes but you.

Sure I will judge a parent if they have an older child and they can't seem to use utensils even though they have been trained to do so. However, after being around the child for a while I realized she was just being obnoxious in order to gain attention. She knew what to do, but refused to do it because it got people to focus on her. The more we ignored her the worse her behavior got until she had a break down. I then felt bad for the mother who I had previously judged negatively.

Ddpspd, have you tried turning off the lights and/or sounds in the room where your son is having his tantrums? Some tantrums are just expressions of frustration, but with a SPD person they can be the result of being overwhelmed. When I start to have tantrums as an adult, I go hide in a cool, dark, quiet place until I calm down.