"Then fork'an do it yourself."
While the ability to fork *is* a major advantage, that doesn't automatically make "Don't like it, then fork it yourself" (or some variant) a reasonable response to any criticism of an open source project, and (IMHO) certainly to this one. Else you could use that as a comeback to *anything*(!)
I mean, aside from the fact he might not have the skill to do this, are you seriously suggesting that he should fork it just to have his <blink>? Of course not! :-)
Just because something's open and/or free-as-in-beer doesn't negate people's right to criticise minor aspects of it. Obviously, if they start getting overly entitled (particularly if the complaining "user" is a large company), then, yeah... you can tell them to go fork themselves.
He made a reasonable point; one which (as a generally happy user actually typing this on Firefox) happen to agree with (though IMHO the default option for blink *should* be "disabled"!!)