You don't have to understand why people hate Spurs, just accept that they do.
Hate is simply a personal reaction to something, an emotion, it needn't be cause to call the police (there are other names for the kind of hatred; racism, misogyny, homophobia etc) I think it completely normal that football fans will 'hate' another team and/or irs fans. It's not compulsory of course but it goes with the territory. People hate all kinds of things; baked beans, strawberry ice cream, double parking, Harry Stiles (I'll bet someone chuckled at that, and thought 'quite right too') Hatred exists within most people, often for reasons the person themselves won't understand. Admittedly, it's what they do with that can cause problems but I think for the most part hatred is a quite normal human emotion. Don't make into something it's not.
If the word offends then read it as 'I don't like' with a bit of extra zest.