Did you misread my question? If Oracle is as hard to get into as Google or Amazon as you claim then you can get past an interview at another company too. There's no reason to choose Oracle.
First, the facts.
* I could clear Oracle interviews and get an offer. I applied for a RDBMS development position in Oracle ST.
* I could also clear Apple interviews and get an offer. Apple interviews were easier than Oracle ST's.
* I could clear interviews in several startups and other small companies too.
* I could not clear interviews in Google. I did not get an offer.
* I did not apply to Microsoft, Facebook or Amazon.
Now, the reasons.
* Oracle ST (RDBMS) provided me an opportunity to work in system development in C and ASM language down to the level of Linux syscalls and memory management (think custom memory allocators, designing locking semantics, distributed file systems).
* I was almost ready to join Apple because the offered work was quite similar to Oracle's and the offered salary was about 5% more than Oracle's but Apple's stringent security policies turned me off. I learnt that Apple would dictate what I can and cannot discuss with my wife. I learnt that I cannot discuss with a friend within the same company what I was working on. All of this may be reasonable from Apple's perspective but I wanted to work for some place with more open culture.
* Most startups and small companies I could get offer from required me to work on web services in Java, Python, Node.js, etc. This kind of work does not interest me.
* I could not solve all the algorithm problems asked by Google but I found Oracle ST's interview a little bit easier. I could solve most of Oracle ST's interview problems and got an offer.
* The openings available in Microsoft, Facebook and Amazon did not interest me. Moreover, I felt I was under-prepared for Facebook's interviews. I felt I was well-prepared for Amazon's interviews. I have many friends in Amazon and I don't find them happy due to long working hours. I learnt that they require developers to provide on-call support at add hours. These things scared me a little bit. Due to these reasons I did not apply to these companies.
So considering the offers I could manage to get and my love for system programming, I had a strong reason to choose Oracle over the other offers.
Why is it so hard to believe that everyone working in Oracle would similarly have their own reasons to choose Oracle?