I cared more when I was younger, but even then I wasn't likely to take offense. Frustrated, perhaps, but usually not offended. There are exceptions, and interesting enough that guy in the article is an example, of claiming bisexuals are just gay, though these days I more roll my eyes at it. But if so many bisexuals didn't suffer so much from attitudes like that (especially when it comes from a group that really should know better AND should know that the more we hang together the less likely we'll "hang separately") then I'd be inclined to just sigh and forget about it.
Even in my younger and passionate years, I had interest in and respect for many who held opposing views from myself. I'd even recommend authors who promoted views I didn't agree with just because their views were so well explained and presented (I probably gave my personal caveats about it, but I respected those views). There was one guy on another fanboard that I used to argue politics over all the time (about 10 years ago when I was more passionate), but I genuinely liked him, and when he lost his computer I contributed $60 to the fund to get him a new one and felt relieved when he joined back with the rest of us (and I felt grief when he finally died). And I have changed some deeply held beliefs over the years, but it's a slow process (and for the most part my views just became more moderate, though a few went through some radical changes).
I think it's because I don't equate ideas with the person, that I recognize under different circumstances and life experiences that I might think like other people, that is I could've been them, and they could've been me, had life dealt them (or me) different cards. While I can think people are evil (defined as intentionally seeking to get ahead by inflicting harm/oppression on others, even if only by proxy, this is especially true when it's over sensibilities rather than survival) or stupid, I don't automatically think those things because they hold a different view from me. Heck, I distanced myself from those who seemed like kindred spirits on the surface but were not people I liked or respected when I got to know them even if we did share many beliefs.
On top of that I like to "shop for new characters" and such for my stories, and I also like to understand my characters, so if I'm not careful then I might find myself "studying" someone to better understand them to put them in a story (with enough creativity that hopefully no one, not even the person I based the character on, would realize who I was basing the character off of), and most people don't want to feel like they're under a microscope (though me and other authors, including a published one, exchange some personal stuff understanding that we're putting each other under a microscope trying to get characters in our story right). And when I write, I can even find myself sympathizing with many of the bad guys I set up as villains, or at least find them intriguing somehow. (I believe I mentioned in another thread in this forum recently that I was surprised in getting choked up when a villain I was tired of finally died, but no matter how sad it was, I still thought he needed to die.)