Do you thinking was because they knew she was special or was it more of a gender thing?
Most Helpful Girl
Because they were from two different worlds.
Her parents represent an uneducated world without imagination. They accept what is fed to them (on TV).
Matilda, on the other hand, disregards "societal" (her family's) expectations and standards and finds her own path and escape via books.2
Most Helpful Guy
I believe it's because her family lived a "cheat through life/selfish" lifestyle and Matilda's mindest and actions conflicts with, causing conviction, resulting in retaliation from the family towards Matilda. Ironically Ms. Trunchpul (misspelled, don't care lol) could have fit into her family as a long lost aunt.1