
Originally Posted by
Azhure
Personally, I don't think Filch hates the teachers, just holds a bitterness that he's no doubt had ever since he realised that he was a Squib. He'd be jealous, but still have respect for witches and wizards, as Elf said.
After all, if he hated the people he worked with so much, why would he stay at Hogwarts, of all places? It's basically made of magic.
Also, I'm sure some of the teachers would pity Filch because he is a Squib, and I doubt he would like that, so that's why he keeps mostly to himself (and his cat). That is, if the other teachers know he's a Squib. It might just be Dumbledore... I'm not sure.