I agree people skills are extremely valuable. I wouldn't be where I am if I didn't have some people skills.

But, to be contrarian and to agree with TravisDBA, I have worked with people who have no people skills, but they deliver. They exceed expectations and they are brilliant at what they do. While it'd be nice if they had people skills too, there's still no comparison to someone with more people skill and less technical skill (in their role).

I would argue there's a difference between lacking people skills and being rude/arrogant/short-tempered too. While people without people skills can come across as rude or arrogant, it's a question of intent. Are they being arrogant because they are an a**, or because they know what they're talking about? If the former, then yeah, that shines through. If the latter, anyone who works with them will quickly gain respect for what they have to say, regardless of initial impressions.