> If your goal is to take over the market quick, as many here would like, maintainability is a very low priority aspect of your code base.

Is it? How long do you expect to keep your momentum after "taking over the market"?

Anecdata time. I once joined a 3 year old project that had ground itself to a near halt with this philosophy. The project's lead seemed almost allergic to the word "refactoring". It had accrued so much tech debt that I was the third "new guy" to join in less than two years, after the previous attempts to hire had successively faltered within 6 months, because my predecessors couldn't deal with the unmaintainable mess. I made it to 9 months.

Maintainability is not tied to OOP or functional, but rather to how much a team cares to manage the cognitive load that comes attached to having to deal with the code base. When that becomes a genuine priority, the code tends to be written with concern for the next human mind's ability to interact with it. And when it makes sense in that one pursuit, functional, OOP, DRY, WET all become valid -- even seductive but toxic affordances like inheritance can sometimes be useful in the right context.