[izacus]

In many many cases this doesn't work and it crashes and burns the whole project/startup company when its necessary.

Sometimes messing up your fundamental architecture means that you hit a refactoring your company won't survive (while your competition grabs all the customers who wanted that feature your architecture doesn't allow).

This is where experienced lead engineers earn their worth - they understand which parts cannot be fudged and fixed later and need to be there from the get go.