Yes it's not too hard or too different, but have you ever tried getting non-developers to use IRC? Finding a desktop client is confusing (which one is best being the first question) and even basic setup can be daunting (servers, ports, channels etc).
Slack, Hipchat and others however can be easily set up and used by pretty much anyone in a company. IRC is great for companies which only have very technically proficient employees, however that's not most companies...