The thing is that both Mermista and Entrapta are right and wrong.
Entrapta communicates her appreciation and love for other people in a different way than the other princesses, Hordak understood that, and that is why they get along so well.
The issue that was brought up by this is that the princesses never truly took the time to understand how Entrapta's mind work, they expect her to show her appreciation for the others the same way everyone does, but she said it herself, "I'm not good with people, I'm good with tech".
On the other hand, Entrapta needed to be snapped back to reality, her hyperfocus and lack of awareness of the environment is particularly dangerous, specially in this situation, and as such they needed to pull her back.
They're both right and wrong in different ways, but don't expect the Twitter fandom to get that because they can't comprehend situations that aren't entirely black and white.