Now why would I assume that? There are times when you need to generate a big report, and just the SQL can take that long or more. But typical web requests for typical applications are not like that. DB queries shouldn't take more than a couple hundred milliseconds for "typical" application requests.
Even counting that, the comparison is also not necessarily correct. In some cases, perhaps the C++ code would have taken 0.1s, where the ruby code takes 5s. In fact, 50x is about the slowdown you used to see for ruby in the programming languages shootout, and it is still pretty bad. [1]
