I'm willing to meet you half way D... we'll call it a 'singularity' if you wish, however the problem arises in that the term is usually applied to zones which defy our current understanding of physics. They are thought, as you know, to exist at the core of "black holes." Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density, which is precisely the problem in your application of this definition of the term to the universe. It is generally agreed that it began as an infinitesimally small, infinitely hot, infinitely dense, something- a singularity, if you wish, sans the squishing. Where did it come from? We don't know. Why did it appear? We don't know... and possibly never will...
My copy of Science says "...three British astrophysicists, Steven Hawking, George Ellis, and Roger Penrose turned their attention to the Theory of Relativity and its implications regarding our notions of time. In 1968 and 1970, they published papers in which they extended Einstein's Theory of General Relativity to include measurements of time and space. According to their calculations, time and space had a finite beginning that corresponded to the origin of matter and energy." Certainly sounds like an apt description of ex nihilo, wouldn't you agree?
Contd.