Are you referring to professional writers specifically, or are you including aspiring professionals and/or hobbyists?
I've met a fair number of professional science fiction and fantasy authors over the years. Most were polite, friendly people. A couple of them were even more friendly than one would ever expect (an invitation to accompany them to the Calgary Zoo the day after the convention; 8 of us took them up on that invitation and had a wonderful time).
Of course the main reason they accepted the invitation to the conventions was to promote their writing and hopefully acquire new readers, but some were also genuine fans of others' work as well and were there because they plain enjoy science fiction conventions. And the ones I used to attend (NonCon and Con-Version) always had the main focus on writing. The main guests were always professional writers - never actors. Other guests included writers, editors, artists, publishers, and local/regional educators - university professors, people from museums and the planetarium, and one year we had Dr. Phil Currie, who runs the Royal Tyrrell Museum of Paleontology here - a world-class museum/research facility.
So... are any of these people overly conceited, vain, nose-in-the-air types?
Yep. A few of the ones I met were promptly moved to my "Do not ever buy this person's stuff ever again because I refuse to support an author who is rude/disrespectful to his/her fans." Three of those people are Orson Scott Card, John Varley, and Lois McMaster Bujold. And while David Gerrold was polite to me, I heard that he was a bit rude to other people.
Robert Silverberg is content for someone to run his Facebook page for him and promote his books and short stories, but he prefers to do his online interactions with his fans on his Yahoo! group. I joined that group some time ago, and it's pretty nice to be able to ask a question or make a comment and get a reply from him. He just had his 81st birthday last week, and is still attending conventions. I first met him back in the '80s, and he's one of the very few people who were GoHs at Con-Version not once, but twice.
TrekBBS is a Star Trek forum where quite a few of the professional Star Trek authors and scriptwriters hang out. For the most part they're polite and supportive to each other. I wish I could say that they're polite to the other people... but two of them made it on to my "Do not ever buy anything from this person ever again" list thisfast. I really don't appreciate a pro author sticking his nose in the air and snottily telling me that if I don't get paid to write, that means my opinions about Star Trek are less valid than his opinions. I readily accept that his opinions on the publishing industry are more valid than mine, since he works in that industry and I don't. But there's no way that he gets to tell me that only professional authors' opinions count when it's Star Trek in general that's being discussed.
On the flip side, however, are the ones who are genuinely interested in their fans' opinions, not only of the novels, but of other things. We do have to be careful never to post fanfic or story ideas in the TrekLit forums; one person didn't heed that, and as a result one of the pro authors announced that he'd just had to cancel one of his novels. He'd seen the person's post and it was too close to what he was currently working on. To protect himself against any possibility of being sued, he had to stop writing that book. A couple of the pros post in other areas besides TrekLit, so a few times I've put my post in spoilers or with a warning for Greg Cox and Christopher Bennett to not read the post because it contains story/fanfic ideas. I don't worry about the others, because they don't participate in the non-Lit forums. And honestly, if David Mack has to cancel a book because he accidentally read one of my posts outside of the Lit forum, too bad. He's one of the ones banned from my bookshelf.
Now when thinking of specific Canadian authors... Margaret Atwood comes to mind. She's an amazing author, both in her fiction nonfiction, and it's no exaggeration that some people think of her as one of Canada's living national treasures. But she's got this hangup about anyone referring to her science fiction novels as what they are. There is no way that books such as The Handmaid's Tale or Oryx and Crake or her other more recent ones could be anything but science fiction. But because they don't have bug-eyed monsters, spaceships, and ray guns, she doesn't think they're science fiction.
Well, she's got a valid point that if people go shopping for a Margaret Atwood book they're either going to look in general fiction or Canadiana. They're not going to look in the science fiction section. But if she would allow her SF books to be sold there as well as in the other sections, she would pick up new readers.