First thing to note is that Firefox is largely irrelevant versus Chrome and Safari in terms of marketshare.

Chrome no longer displays EV certificates differently, I believe, that about 2 thirds of the market.

The second thing is (2) is my previous comment: Even if an EV certificate is displayed differently, does anyone care? Does that impact my business to make it worthwhile?

The general public could not care less, imo.

You're saying that Firefox's 9% is irrelevant versus Safari's 3%?

That's not the point of my comment both regarding EV certificates and regarding relevance of Firefox (and I don't know where you got those stats).

You are clearly excluding mobile browsing stats.