Its a preference of taste, tech-savy individuals will prefer a VPS cause they feel in full control of their website hosting environment, not to mentioned the flexibilty to install or remove any software. If you are hosting some sort of community like for example forumweb or any other legit website which would require more than 150-250 emails to be sent per hour. I know this might sound odd, however some people don't like cPanel or plesk, therefore they wish to have other control panels like VestaCP or CentOS WP.
Comparing different virtualization types for webhosting is quite pointless, OpenVZ, Xen or KVM, at the end of the day if the provider doesn't oversell their server nodes or performed a proper optimization to the nodes they will all have similar performance benchmarks.