Memes

Homophobia: irrational fear of, aversion to, or discrimination against homosexuality or gay people Merriam-Webster

Homophobia can take many different forms, including negative attitudes and beliefs about, aversion to, or prejudice against bisexual, lesbian, and gay people. - Planned Parenthood

Homophobia encompasses a range of negative attitudes and feelings toward homosexuality or people who identify or are perceived as being lesbian, gay or bisexual. Wikipedia

Negative attitudes towards homosexual people and homosexuality which may be manifested in discrimination, hostile behaviour, or hate crimes. The term was adopted in 1972 by George Weinberg (b.1935), an American psychologist. The use of ‘phobia’ has been criticized as implying a pathological and irrational fear rather than a form of prejudice analogous to racism. The term is sometimes reserved for more extreme forms reflecting hatred and revulsion, the term heterosexism being favoured in other cases. Homophobic attitudes have been associated with conservative ideologies and authoritarian personalities. Extreme homophobia is often attributed to unconscious homosexual desires but it can also be due to ignorance or function as a means of gaining approval from a reference group. Institutional homophobia is reflected in laws, policies, practices, and the history of invisibility of gay people in the mass media. One theory is that the social function of homophobia is to enforce rigid gender distinctions (see also heteronormativity). Internalized homophobia refers to gay and lesbian people themselves adopting negative attitudes about homosexuality from socialization into a homophobic culture, leading to denial or self-hatred because they feel that they cannot live up to dominant cultural gender expectations. Oxford Reference

Categorizing homophobia as simply "persistently and unreasonably afraid" ignores a truly enormous amount of what homophobia actually is. W&G playing on stereotypes isn't inherently bad. As you point out, there are many sitcoms and other shows which will play on stereotypes. Where the homophobia comes from is how it treated those gay characters. Notably that they were treated almost entirely as set dressing. Will and Jack are completely unimportant to the show. No decisions they make have any lasting impact or importance to the plot. In fact, their decisions are barely followed at all. In Season 1 or 2, Will loses his biggest client and as a result has to shut down his firm and start over at a new one. When he does, his boss ends up getting involved in more of Karen and Graces episodes than he does in any Will episode. When Will has a problem with his brother they do two episodes on it, mention it once in a later season and then never mention it again. Meanwhile Grace has multiple episodes about her problems with her mother. Even the episode where Will comes out for the first time to anyone? It's entirely about Grace.

How Will felt is used for comedic set dressing while Grace is the only one who's focused on for any emotional impact. In the later seasons, Will ends up in a relationship with a cop and it goes poorly. Again there is like no time given to this. In fact let's talk about relationships in general. How many relationships can you remember that Will had? There's Michael, a character who is only ever seen once but is referenced constantly to belittle Will. There's Vince, the cop boyfriend that I mentioned. That's fucking it. At least for the 8 season long original run. What's insane is that Will has had more female romantic partners than he has multi-episode relationships. Seriously. He dated his high school best friend (who wanted Wills babies which caused a whole thing with Grace being a controlling freak), he dated Grace and then he had a one night stand with a random woman after he told Grace he was gay. Which, of course, Grace immediately makes about her and gets angrier at will.

The Gay characters of Will & Grace are used entirely for comedic purposes and have no depth or important to the show meanwhile the straight characters have endless season long arcs about their relationships (Grace and Leo, Karen and Stanley are just two blatant examples). They are completely flat and two-dimensional and was an outright betrayal to the gay community by repeatedly reinforcing stereotypes and abandoning the gay community for the sake of a laugh. Anything that could be seen as even slightly subversive is immediately washed away as it's turned into a joke.

I love Will & Grace. I really do. Having that representation was important for me when I was younger and was important overall but it must be equally as important to remember that Will & Grace undercut the gay community at every chance to make straight people laugh.