To try and answer your question, you must first understand that everything (or almost everything) comes down to money. The perception will be that someone who's upbringing was on TPs will be a greater training risk than someone who has already had jet experience (higher altitudes, different ladnding perspectives, faster climbs and descents, longer spool up times etc). Maybe not very accurate in gaugung an applicant's potential, but there you are, it makes the HR department's job easier.
Also, remember that most senior management pilots are still ex military fast jet and they will always favour those with jet time over someone without regardless of cost or risk.
What I can't answer is why they'll take a 250 hr cadet with a self funded JOC on some clapped out simulator over someone with 2000 hrs turbo prop who's been flying the line for a few years. There must be a saving somewhere.
Funny how it argument against itself.
-Jet Experience is worth more when transition to another jet aircraft hence why TP guys are abandoned. (So far it could be logical...)
-Later on stating. Strange that 250 hrs guys with no hands on Jet experience is more qualified than a TP guy with 2000 hrs. (hmmm....
)
-The only conclusion from this argumentation is that "Experience" makes you less good for a Jet job when trying to transition from a TP job.
-For this reason. Make sure the first flying job you get is what you want to do for the rest of your career.