No Great Lakes pilot has been denied a jumpseat for a non-legitimate reason in recent memory. I j/s'ed on three different flights last week, all crews were cordial, as has been every crew I've ever dealt with. Further, Mesa crews (with the exception of Freedom A-listers) jumpseat on us and every other carrier without difficulty or aspersion.
For the record: You'll find once you get your airline job that these internet forums are polarized to a greater degree than the real world. Around these boards there's lots of generalizations and branding with titles and categories (*****, scab, defender of all that is just, etc.) In the real world of the airline industry it's shades of gray. Compared to members on this board, the average line pilot cares a lot less, and has much less passionate feelings about airline politics. Such mellowness, while a blessing on one hand, is also the source of our professional downfall. Your average mainline captain, if he had to guess my salary, wouldn't get within $20,000. Heck, he probably couldnt guess his FOs compensation with any greater accuracy.
I'm all for solidarity and presenting a strong, united front to management, don't get me wrong. But don't get tied up in knots over this one. For the moment, don't go to GoJets, anywhere else you're safe.