But it is not default. Does a normal user have an urge to change the default browser even it performs worse than non-default browser http://www.reddit.com/r/Android/comments/12o9oy/why_is_chrom... ?
I assume most people install Firefox because it's better then the default browser experience. The argument in the parent comment is that this isn't the case so those that would normally go out of their way to install it have no reason to do so.
e: Or maybe I read it incorrectly? Firefox is a better mobile experience? If that's the case, I'm not really sure what the parent comment's argument is.
Defaults are a big deal.