I'm sure that many, many people who work on weekly TV series care about profitability. Their paychecks depend on it.
Perhaps they do care but the part that effects stuff is the decisions that many rarely build around profitability as they have other things in mind more immediately relevant to the job they are doing and perhaps do not feel like they even know what people like other that what they make seems to be popular. There are makers who constantly think about marketing but then there are ones to whom it may just pass the mind occasionally but not really drive things.
Maybe some bunch decides a show about Klingons is going to be really fun and some guy figures they're iconic and convinces another one that it has a good chance of selling
Stuff ends up happening mainly for other reasons than perceived profitability, even if that often is a very influential, often final part of the decision making process.