That seems quite an odd example. The quote seems pretty innocuous, also, branding a whole group of people as a ‘horrible Sub-species’ says quite a bit more about an individual (yourself), rather than anything/ anyone else.
All clubs have some supporters who are great people, and some who are not, in the same way that society does. Generalising and ‘othering’ can be understandable in the heat of the moment, but it’s a little strange in written form.
I support Liverpool, and I would hope, I’m quite a decent sort, not a member of a ‘Sub species’.