The time to market for the MIT approach is just too long if your revenue relies on actually shipping a product that covers the cost of the next iteration that will move you from 80% to 90%, or even 60% to 70%. It's an old joke, but in the long run we're all dead; and waiting for the production of an ivory tower implementation won't work out well. If it's all academic, and there's no commercial pressure, well, have at it. There's not much at stake except reputations.

Furthermore, in the real world, your users' requirements and your internal goals, theoretically covered by "the" design, will change. Not everything can be reasonably anticipated. The original design is now deficient, and its implementation, which is taking too long anyway, will be a perfect reflection of its deficiency; and, not fit for its new purpose.