Putting aside all the dick-whipping-out-and-measuring…
The topic of arrogance and personal conviction and expression is a good one. Just the fact the original poster had the thought to pose the question to me shows good thinking. Much better than just going with the convential wisdom, acting arrogant, and getting unplanned results!
I believe there is indeed a place for personal conviction and objectivism. The key I believe is the end goal of those convictions.
From my perspective, it is true arrogance and a negative expression of self when a person forces his/her thoughts/decisions/opinions on others for the only benefit of their own ego. This can be done by inexperienced designers saying they know everything, or experienced desigeners pandering to image and celebrity.
Aside from the exception (surely there is some place/use) for celebrity designers, (a whole different discussion!) this I generally think is not welcome in the professional work environment. The end goal of communication, discussion, etc. is not to convince someone how great your are, or why you are right, but finding the best solution to a problem. You may be 100% correct, but acting like a selfish, self-assured fool will get you nowhere fast, and only cause resentment.
I dont think however, that this is what the original post was about. Giving credit and a common sense perspective to the question, I think the comment about arrogance is more focused on the seemingly confident attitude and personal conviction that often accompanies sucessful people.
For sure, to some this can feel like arrogance. In my experience, however, the big difference is that the end goal of the successful person is usually focused correctly on the solution. It is why they are successful. Personality alone will not make you great. Finding a good solution will.
No one is saying that you cant be confident, or that having an opinion or personal conviction is wrong. If you do it for the sake of making your image stronger, or ego however, I think you have every right to expect people slagging you and thinking negative things.
For sure some people have an inflated self image and are egotistical. In my opinion however, this is thankfully the exception rather than the rule. Best you can do is ignore all the tongue wagging. Certainly if these egotistical people have less skills than ego, they wont be going far.
All in all, work on your skills. I have never seen “ego” or “arrogance required” in a job posting.
Related to this, I recommend every designer should some time read Ayn Rand’s The Fountainhead.
In addition to being a great comment on challenging the traditional viewpoint of a market through design, many of the character points that make the book relevant 60-something years later touch on the basis of personality, selfishness and arrogance.
I just so happen to now be in the process of re-reading it (i try to read it every few years or so), and its amazing how well it actually fits this whole discussion.
R