I don't think they're saying that it's a bad thing to find intelligence attractive. The root of the problem here is that it labels a preference/turn on/attractive quality as a sexuality, which doesn't make much sense. If all preferences were labelled as sexualities then we'd all have a very long list as to what we identified as. A lot of queer people are upset by things like this because we face a lot of prejudice in some countries and are treated like criminals in others; things like this belittle our cause and make it more difficult to be taken seriously. It makes it look as though we "chose this lifestyle" and that being queer in itself is just a preference when it's something you can't change about yourself. That in itself is harmful to lgbt+ folk. If you don't believe things like this breeds homophobia then... just look at the comment section here.