Going through the book "Enterprise Architecture as Strategy" by Jeanne W. Ross, Peter Weill, David C. Robertson, I have found an answer to the question that I had for a while: who is the first: business or IT (egg or chicken) in regards of the product definition. From the personal experience, when choosing/developing a new application, collecting requirements from the business users and implementing it in the product it is not always the best way to go, because business users can be unaware of the industry standards and trends.

Stages of enterprise architecture maturity explain who defines application in organization. It depends on organization's maturity stage. There are 4 stages of maturity: business silos, standardized technology, optimized core, business modularity.

In business silos local business leaders are the decision makers, in standardized technology - IT and business unit leader, in optimized core - senior management and process leaders, and in business modularity - IT, business and industry leaders.
Interesting is that even if IT understands the "nearsightedness" of the business decision makers, there is no much that IT can do to increase the organizational speedup in it's learning towards a higher stage of the architecture maturity. It takes time, educating and learning!