Im a skippers pilot, its no longer 2007 - so the above posting doesnt give you any indication of the situation now.
Fact is, its a breath of fresh air to step out of a a piston twin into something bigger with aircon, a hostie and isnt restricted below A100. People will always move on, thats natural and not the concern here. If u come from a piston twin, and want to progress this is a step in the right direction... with a small paycut as an F/O, then you live comfortably in a year or so when u get command. (command upgrades is anyones guess, looks like around a year at the mo)
So if you currently fly piston twins and think that going to a regional like skippers is a bad moved based on what people have said "has happened" then you need to tear your license up and get a job at the minesites that skippers and other regionals fly to.... or go be a cadet and get in a widebody with NFI what you are doing.