My observation is that earlier on in people's careers they tend to be more certain about the limited experiences they have had due to a lack of contradiction..
Of course, if you keep repeating the same limited experiences this will only be reinforced ;)
My experience is that fresh grads are aware they lack experience and are appropriately modest in their judgements of technologies, whereas people with ten years of experience are dogmatically confident that certain technologies are good or bad.
I've found that sometimes people have done one thing their entire careers and, therefore, think that's the only solution to everything. And I think that's more likely when your entire career is a couple years long.