Yea, I've seen it both ways, from you had to have a bro in management to get looked at (and a certain pedigree was almost mandatory) to "if we get a letter of recommendation before the interview, that's the kiss of death".
Not sure where the middle is. In my admittedly foggy memory, I remember NWA had a program where you could recommend someone, but you actually HAD to have flown with them in a previous life in whatever version of line flying you did. You couldn't just go rent a 172 for the afternoon and shoot some touch and goes.
Richman