Well it is true. Both planning and execution are beeded for a business to be successful. If one fails the other fails also and the whole system collapsee. But then again there are success stories where they opened a pop up store because that is all they had and eventually grew to a international multi million dollar company.
Building a business forecast before executing your business model is very important along with questioning your whys! Besides, the more perfect your model is, the more successful it would be if you take the start.
Majority of the new people in the market who wants to invest but somehow could not is just because they lack the initiative that is very crucial for starting any business. Until you do not have that courage to loose the money you look forward to invest, you might never start.