I can understand scientists wanting to use scientific names...but why do perfectly normal laymen suddenly go into "jargon gear" and start using the most esoteric terms possible? I have a neighbour who suddenly told me her son had "Coryza". I was very concerned until I realized that the little boy had the symptoms of a common cold.
The English language may have roots in many other languages, and some of those terms may still be used for technical terminology. But to me, my relative who talks of a "myocardial infarct" instead of a heart attack, is sort of lording-it-over-me, hoping to impress me with his knowledge.
I may write indifferent verse but if I then mention that I wrote it in iambic pentameter, that makes me SOUND more learned. I may daub a painting but I can talk about my chiaroscuro techniques.
I suppose that is it...to use technical jargon as if it were everyday language makes the user feel that s/he can impress the hearer about the superior level of knowledge about the subject.
This kind of jargon extends towards prolix (there I go!) language, too. Insted of "now", I say, "at this point in time". My favourite sentence is, "At the end of the day, at this point in time, the need of the hour is to address the burning issue and put back the clock." A whole lot of FOBi (see subject title) that is "sound and fury, signifying nothing".
This works towards my general (yes, like all generalizations, this is not totally true!) theory that very often, an increase of knowledge seems to be accompanied by a proportional increase in ego. When Knowledge walks in, sometimes Humility walks out.