It all depends how you look at this. I work for ryanair and work with new cabin crew all the time. This may not be the best opportunity in the world but at least it can give you a chance to see what it's like. Some don't last five minutes, others stay for years and progress trough the ranks.
I'm sure you would find working for some other airlines more rewarding, but are they offering. Is your glass half empty or half full?