I think companies use Jargon to help instill a cult community on purpose. I just proposed the idea of creating such a glossary as you mentioned. I can't change a company with close to 100,000 people so I assimilate to get my pay check.

One company I was at had a jar in each conference room. When you used an internal name or acronym without first defining it, you had to put a $1 in the acronym jar. This was used to buy the team lunch. They had to abolish the policy as it was seen illegal to force such behavior. It worked very well while it lasted though.