It's not that I don't believe that Oracle can scale better than MySQL, it's just that I haven't seen any convincing data that it can scale so much better that it's worth the cost. I'm no expert, so maybe the data exists. I just haven't seen it.
Seeing the amount of ugly hacks people are willing to come up with and employ and features they are willing to cut, just to handle trivial loads, kinda makes me think that MySQL can only be considered free if your time is worthless.
Also that he says SQL database and not relational database. The whole article reeks of inexperience.
The retail price (I know discounts can be negotiated, but for a point of reference...) for MS SQL Server Standard edition is $5000, enterprise edition is $25000. I have never had to research Oracle prices but I understand they run even higher.
I worked as an MS SQL Server DBA for a while for a mid-sized company, and I wrote and employed some "ugly hacks" to emulate some of the Enterprise features because management at the time was unwilling/unable to pay for Enterprise Edition.
Google is one of those excellent examples of a non-sql datastore that works just fine and seems to blow the socks of anything the competition has come up with to date.
DB2, Teradata and Oracle users regularly tackle problems 100x larger than MySQL can handle.