I think they have a few things to fix before they go public, like the insane amount of money they've been spending on marketing.
With this bad reputation and even some boycotts like "leave godaddy, they support sopa" it is obvious they don't have a good reputation and their service is "good enough to not bother switching"
I don't think they'd grow without massive marketing.
[1] I dont know how accurate this data is, although it doesn't look too far from truth http://www.webhosting.info/registrars/top-registrars/global/...