Does a long time to solo hurt your chances of becoming an airline pilot?
It depends on the final product presented to the airline.  If an airline had two candidates, one of whom soloed in 10 hours and did well in a Sim Eval but was self absorbed, didn't like to follow procedures if he/she knew better, and didn't work well with people, and a candidate who took 30 hours to solo but was a team player, can get along with anyone, was an eager learner and was emotionally mature, and did a passable job in the Sim Eval, they'd take the "slow learner" in a heartbeat if they were confident the candidate could get through the type course.

In the airline world, raw flying skills are an important baseline, but big picture personality related issues are just as important and personality problems with crews are a bigger long term problem than how long it took someone to catch on at the start.