Dad wants us to throw away the last plastic "plate"

I'm really upset that we're going to have to throw away the last plastic "plate" (it's and its old pals, were all lids really for plastic bowls we never really used)- because it's getting "damaged" and Dad's is basically a  health nut when it comes to not wanting plastic to come into our bodies.  It's literally the reason Dad had a complete cow the other week to the point of throwing Mom's chair across the room.   I tried to tell them that  I find the dessert plates  that it's hard to cut and dad's response was to talk about "platic coming into our body"  but that's literally had nothing to do with my point?  And Mom said "did you hear what Dad said?" again didn't  have anything to do with my point? 

But until now, I been using plastic "plates" since I was let's say 13. I'm 35 almost 36 now that's about 23 years of me using those plates.   So technically isn't the plastic already inside me?  If I had known Dad wanted us to throw the last plastic plate away today,  I would have used it today one last time before I have to move to the non-plastic plates which i have problems with which I will get  to in one second. 

My parents tell me to use the "dessert plates" and I have been using them.  But there's three problems I have with  the "dessert plates":

1. there's not a lot of room for me to cut sandwiches on vs. plastic plate.  I always need to cut my cheese sandwiches or my half-a-bagel-to-eat lunches.  The dessert plates cause friction compared to the plastic plate doesn't. 

2.The dessert plates also are too hot for me to handle after I microwave the sandwich/bagel  and I also microwave.  The plastic plate are not hot to handle after microwaving. 

3.This might seem minor, the dessert plates are all one design (white and some green) and eventually that will fade away (as has happen to the main dinner plates) vs  the plastic "plates" had some  colour:  orange, yellow and a couple more, including this last one  a dark green colour.     Mom thinks I want something with more then one design but that's not what I want I want options and not have one option because all those plates are from the same set.