I see you're in Canada, but you don't say which system you're talking about - Canadian? European? American?
The simple fact is that there is no legislative requirement for a degree or 'diploma' in any of these systems, but in the USA and in some european countries it is customary for employers to demand a degree as one of their selection criteria. The Canadian commercial aviation scene is so small (in relative terms) that employers there can probably work on personal recommendation and nepotism as their main discriminators, rather than any specific non-aviation qualification!
Scroggs