Whatever happened to the proposal of using . as prefix?

If memory serves, the main objection was about it being hard to see, but is it really? We use fixed width fonts for a reason, and there are other places a dot is quite critical (has any php programmer ever mistaken a .= for a = ?) without it's size ever causing issues.

I think . is visible enough while being aesthetically inoffensive. Am i missing some problem or important past objection to it?