Why Google, MS, FB, IBM, etc. have Failed Products?

Question:
Why do so many products of the best technology-champion-companies; like Google, Microsoft, Facebook, etc.; fail even though these companies have the best talents in the world?

Answer:
Companies often start with One Core Idea (Strength)
and
It is NEVER easy to Replicate their dominance in that segment in other areas.

For example:

1. IBM's strength was always in complex, large Mainframes and they never could replicate the success of Microsoft in the PC market.
2. Microsoft was a goliath in PC, but could never succeed in the web.
3. Google had a killer web 1.0, but never understood web 2.0 [their forays in blogging, micro-blogging, and social networking were all failures].
4. Facebook aced web 2.0, but never understood mobile [forcing them to buy Instagram and Whatsapp].

Great companies have fumbled multiple times trying to come to terms with a newer product paradigm - Sometimes they bought their way out of this mess by throwing massive sums of money in acquisitions, but other times they were not so lucky.

Source:

This post has been fully derived from an answer written by Balaji Viswanathan on Quora.com