One man's preference is another man's "comfort zone". I don't think we create them. We find them. We stay in them because they're comfortable. :) There are any number of different ways people either do or don't stay in their comfort zone. The person who is comfortable living in the same house for years may, on the other hand, be a person who gets out of his comfort zone by, for example, constantly finding his own intellectual challenges. Because of this kind of (sometimes hidden) inconsistency with the different types of comfort zones there can be, I don't believe it is "well known that living in the comfort zone for too long limits growth....dissatisfaction.'
Another inconsistency is this: One person may have so much "excitement" or challenge in his life, there's the chance he may prefer having at least one area or another in which he can, in fact, feel kind of comfortable. Somebody might look at such a person and think, "He won't leave his comfort zone." The truth may be that he won't leave it because he has so many "discomfort zones" of one sort or another in his life, he actually needs that little bit of peace and balance.
The term, "comfort zone", is a term used by people who don't understand the other person and so find labels for behavior they don't (and maybe even can't) understand. Such labeling of behavior doesn't even seem to acknowledge the existence and needs of the individual who exhibits that behavior. As you can guess, I don't like the use of this term for the purpose of interpreting the behavior of someone else (or even oneself). It's a "rhetoric type" of term that's often used by people who need old, familiar, rhetoric rather than respect individual differences and needs between people. Some people who adopt this particular term are as equally lacking in understanding of, and compassion toward, themselves as well.