Why does the paint in my home scratch off easily?

Question

We bought a flipped home in 2013. Over the years, we've noticed that the paint chips and scratches very easily. We always thought this was about bad paint but we have recently started repainting rooms with quality paint. The other day, I scratched a newly painted surface with the corner of a desk. It was barely a rub that resulted in a white, powdery gouge. Is it possible that it wasn't cheap paint but low quality drywall or drywall mud?

https://www.dropbox.com/s/2ahk0mydzwyili3/20200704_103458.jpg?dl=0

https://www.dropbox.com/s/7nq7ssdexklgci9/20200704_103516.jpg?dl=0

https://www.dropbox.com/s/sslvk93nhra9euk/20200704_103531.jpg?dl=0

https://www.dropbox.com/s/zu7en9ihkgw4mt5/20200704_103558.jpg?dl=0

https://www.dropbox.com/s/nvjon3ou13ooyng/20200704_103609.jpg?dl=0

Answer 1

Those pictures lead me to believe that the walls were textured maybe right before the flip and weren't primed and sealed prior to being painted. Now, you've just painted over a weak surface.

Answer 2

No it's not the mud. I have seen this on walls that had 100% new mud and top quality paint but if the surface isn't cleaned before painting the paint doesn't adhere as well due to dust. Imagine trying to get tape to stick on a dusty surface. In your case, if you painted over old paint, same thing. Could be dust on the walls.