I've been working in the last year with SQL Server and one of its competitors, both being used by an application.
Now my team has run over 3 different buffer overruns running the most expensive IBM Unix machine into the ground.
Now this DB installation is being "cuddled" by one of the vendors own consulting DBA on a machine, protected by numerous firewalling sofware and monitored 24 hours by special management sofware. Obviously any documentation or KB docs are not available(Security by Obscurity) for these software or are more expensive than an original Shakespeare manuscript. Some NDA also prohibits these issues to become of public domain.
At the same time my team of developers manages the whole software aspect of SQL Server.
To this point I think that the bugs are really been counted unfairly in the context of the environment:
In the MS world software is being installed on standard hardware and maintaned by standard techies , while other environments are treated as royalty while being only usurps and mostly technically inferior.
In this context of environment SQL Server(please install SP3 !!) really comes out much better than comparables.