The DB is an excellent product. It is not just sales and/or execs relations. I've used ORACLE, Postgre, MySql, SQlite, MS-Sql, and also Firebird. From the bunch, ORACLE is not only the expensive one, it also delivers.
eBay also used Oracle in the past (if you dig back in the past of their architecture/design of eBay).
Oracle SQL might be the fastest, most robust out of the box database, but for a huge deployment like Google/Facebook/Twitter, even out of the box Oracle SQL won't be good enough. It's kind of an unfair comparison.
That's not to say I'm defending Oracle's bullshit, but you gotta put these things in perspective.