I totally agree with you. Capability <strong>"LIKE"</strong> will drive Hadoop adoption, Hadoop should not be seen as replacement of R.D.B.M.S. These are two different tools for made for different purpose.
One common misconception about using Hadoop is that use Hadoop if your data is large. Usage of Hadoop should be more driven based on the growth of data rather than size.
I agree that for the given use case, the solution is appropriate and works fine. Problem mentioned in the given post is not a Big Data problem.
Hadoop will be helpful in case if there are millions of games are played everyday and we need to update the statistics daily e.t.c. For this case, the given solution will hit bottleneck and there will be some optimisation/code change needed to keep running the code.
Hadoop and its ecosystem are not a silver bullet and hence should not be used for everything. The problem has to be a Big Data problem