Seniority is everything here in the US.
Have worked for companies without seniority (Middle-East) and much prefer to work for a company with a proper seniority.
(Even if it meant I had to climb down from a B-747 left seat to a B-727 F/E seat to start with a new company 2 years ago.)
In general seniority is a good thing.
It does not restrict people from switching job, you just have to start at the bottom every time.
