Some of the worst pilots I have flown with have been scabs! They upgraded quick and the majority are afraid of management.

Here is the trend of scabs i have seen:

My seniority is great
Everything is about my comfort
I am lazy
Look how much money I make.
I don't do four days and i don't do red eyes! (How dare they ask me to do that with my seniority!)
This is what I am going to do so lets be on time because it's all about what I am going to do!
Where did the scab captain go? oh there is the scab captain in the hotel van ahead of everyone.

Yes there are exceptions, but the majority I have noticed have these characteristics.