I don't know what the fuss is about here. When offered an opportuntity to make some money most people will take it. Only very rich people can afford to be choosy.
In Adele's case she might not be as rich as people estimate and her career might not last. Not everyone in the music industry can live off their earnings into their old age. One of the members of Blue has just been declared bankrupt. OK I know he's not in Adele's league but some people only have a limited period of time to make the money (models, footballers, popstars). Adele's star may wane quickly, who knows?