The ULCCs certainly provide a nice alternative career to the Big boys.
With so much industry consolidation there are fewer career airlines than there used to be. I strongly believe that the remaining few big airlines are stronger and will survive any recession and provide better job security than in the past. However, there's less choices now then there used to be. If you botch the Hogan at United and fail your Delta interview, your choices become very limited very fast.
Anyhow, I think the ULCCs will grow thru the next recession while the big airlines slow or stop growth. ULCCs are proving to be very successful all over the world. Just not in the long haul markets. And for the record, the ULCCs claim to be generating new traffic and not stealing from other airline