Actually, to arm chair quarterback a little, (no offence intended - I could be wrong), I wonder if mentioning QOL as a reason for not leaving for a legacy wouldn't be viewed negatively in just about every respect by everyone on the panel these days.
Believe me - ALL I care about is QOL! My pay is a distant second. But to 'hard chargers' I'm certain QOL is viewed as a life sucking drain on the bottom line.
And on the other side of the coin, especially with all the changes: Flying tons of redeyes, Denver downsizing, east-coast ops, decreased efficiency, less days off etc. I think juxtaposing F9 with a Legacy and using QOL as the defining factor could come off as a little tone deaf to the good hearted line pilot sitting on your panel.
I personally wouldn't go near that term in an interview but that's just me.