A flow is an insurance policy, nothing more. We all have house, health, and life insurance so why not have a legacy airline insurance too? You might never get an interview at AA on your own and if you do you very well might not get hired and have to settle for an LCC or being a regional lifer. The flow at all 3 will be about the same for someone hired today so go the place with the easiest commute and work on getting hired at another legacy until you flow. I know the common thought is that everyone will get a legacy job in the next 10 years but that is not the reality, many will not get an interview or get the TBNT and be stuck on the outside. There are a lot of people at Delta UAL and AA that now have a job because of a flow that woud have never been hired otherwise.