In my very short time working in the programming field, I've seen two extremes:
It seems like the latter oftentimes happen as a reaction to the former. Where is the happy medium? And more importantly, if a project is moving in one of these directions, what is the best way to move it towards said happy medium?
In my own personal experience, I have found that 'decisions' are my bottle neck.
If this is the case, then :
A 'Proof Of Concept' is a minimal app to prove something. (mine are usually 1-6hrs)
If you have a situation where 2 or more options are equal, give yourself a time limit (like 5 minutes, not 2 months) and make a decision ... any decision, and don't look back.
And trust yourself to be able to deal with any problems you will hit which you did not take into account at design time.