To be fair, I don't think Darren and Lilia have in any way lost their passion for dance and it is their life. You don't have to compete in every competition to prove that. I certainly don't believe they would give up their love for dance just to be famous. In the dance world they woud have been famous before starting SCD anyway. It did read as if you were implying that they were only out for the money and fame now, although perhaps you didn't mean that, but that would be totally wrong I think. Anyone who does know them would know how passionate they are about dancing. Everyone has to make a living out of what they do, and entering a competition is their decision, it is neither right or wrong, they make a decision based on what they want to do.
One of the reasons Darren may not be doing Bournemouth is possibly an injury concern related to his quite serious injury last year, and as anyone who dances will know, it is lunacy to compete if you are not fully fit. He probably has to be quite selective about what he does compete in, and having to dance all the early rounds as well as semis and finals is probably not his best option if he is concerned.