Minimally, it takes a lack of empathy to open a tweet with "My sister is fat"

so I text her some motivation.

so I reinforced her fears that other gym members will mock or judge her. Very motivating.

As an avid gym-goer, I dont know why tf so many of them feel so compelled to belittle others for their weight. Everyone is there to feel good and improve themselves, why discourage them?

I suspect its an ego thing and punching down lets them feel superior. Gym people trend towards egotistical.