This did not catch on when introduced in 2002 because the problems it was intended to address, such as nullifying the power of the big servers, were soon being solved in other ways.
The UML model is more refined and formal, but it remains synthetic and readable because it is intended primarily as a communication device between the team members.
For business users especially, the main concern is that Skype provides an ideal vehicle for delivering malware into the inner sanctum of an organisation, as well as for sneaking corporate secrets out.