I feel his pain. It's hard to only see yourself in negative images.
When you finally see yourself in a positive light - or even a neutral light - it's so important and affirming. That's why Spiderverse and Black Panther and Wonder Woman resonated so hard with people. I grew up gay in the AIDS-ravaged 80's and it was awful. Always dirty, immoral, villainous, less than. It was two decades or so later that I ever saw a positive portrayal. It absolutely fucked me up. Still fucked up, even with every other category of privilege (white, male, educated, socioeconomic, etc). Your mileage may vary; not everyone is wired for it to scar so deeply.
Representation absolutely matters. Positive representation. Plante's reaction is his own, and it's real, and it's not for any of us to judge his opinions and feelings as unfounded or unworthy.
I think the ignoring of concerns is more scarring than the actual characters. Being unseen is one thing - being unseen after you've been seen by that person is absolutely worse. Props to him for putting this out there. He knew what some of those reactions would be and still spoke his mind. Good on him.