AITA for trying to get my parents to change their behavior?

Brief back story, my grandma has dementia and still lives in her home. My mom and dad work full time. My dad’s family has irresponsible 30+ year olds that live with my grandma because they “have no place to go”. They don’t work and barely pay her rent.

For 3 years now, this dynamic has been going on. It’s a full time job for my dad checking in on her and taking her to doctors appointments. The people that live there do watch her, but hardly. These people ask my mom and dad for everything. For example, if they run out of toilet paper. They text my mom, and say “grandma needs toilet paper” and expect my mom to drive 25 minutes one way to get it to them. My dad definitely enables this behavior, because he thinks he’s helping his mom. My mom doesn’t like how these people act, and naturally my parents argue about it. Their relationship is clearly struggling These people also will randomly blow up on my parents and call them horrible things. Basically every name in the book, they’ve said it.

There are 40+ examples of this, but I would have to write a book. I acknowledge that they are doing their best. I tell them they need to stop enabling these people and tell them to grow up. I think they take this personally because they turn things around on me, and tell me I’m trying to start an argument. I defend my position, but they only hear things as “I must just be a shitty parent then if this is how you see things”. Obviously there is so much more to this but can’t type a lifetime of issues.

Am I an asshole for just trying to get my parents to do things differently and be better?