This is so true. I have worked with several legacy code bases and I had discovered that in two opposite settings.

When I was developing on a quite malleable and a bit unpredictable language, I wished it would not be like that.

When I was developing on a less malleable, more predictable one, I was thankful it was like that!

I think it makes sense when you view a program as a cultural artifact. If a programmer has much freedom, so much that he is able to define his own conventions down to how to code the tiniest thing, he should really work hard to pass this "culture".

Unfortunately, as we all know, we seldom have the time and the means to share views about the code. So, indeed, the more universal the idioms, the less we jeopardize the understanding of the code by our peers.