Love the use of the word supposed there.
Dragon is built by Space X that has a track record of blowing things up.
Maybe parent feels like rocket science is a field that should have few launch failures?
I can't give you a quantitative answer since I'm usually focused on new research rather than what company/nation did said research... but their stuff does seem to blow up on the launchpad more often than NASA's :-)
Unless you count test artifacts, an actual catastrophic failure of a rocket on a launchpad (or even in flight) has been rare in the last 10 years.