It's wildy successful for a reason, which is that its primary usee is by web browsers for document transfer. And as a result firewalls allow http over port 80 o

It's wildy successful for a reason, which is that its primary usee is by web browsers for document transfer. And as a result firewalls allow http over port 80 or https over 443. For a lot of cases you simply cannot communicate at all unless you use http. The reason for its success is that there is simply no other choice whether it's good or bad.