That sounds like the social skills issue. If the interviewer signals change of topic is needed and interviewee does not follow, you definitely know the person has limitation in the social skills area. Also, if the person can not talk about practical aspect, they can't.
However, "15% actively dislike overt CS discussion" does not suggest companies that merely wanted to talk about practical aspect and could not. It suggest companies that are hostile towards people who attempt to talk about theory - talk about it too much and you are primary theoretical despite being also capable practicaly.
In any case, I do not want to work somewhere where I am expected not to talk about what I know (beyond the normal "don't have long monologues they areally not interested in"). I want my collegues to talk about what they know too.
I also think that if knowing something harms me in the eyes of the company, then I do not want to work there. Such environment must be demotivating for learning. And i need to continuously learn. It is ok if they don't care and it is awesome if they are interested in different things that me (I can learn from them). Especially if we are talking about small companies where people who interview you reflect wider culture. Working in environment where people sort of punish you for knowing things they don't know is road to mediocrity. I want to work with collegues that will motivate me to learn - that is super important in length term.
So that leaves 85% of companies where I can talk about theory and not be harmed at all.