You are right, it's probably a lot less than that.
The bug quality is higher than you might expect, because you have to register with bugzilla, and most bug reports are with development versions, as bugs are shaken out of new features. There are very few bugs in released versions, and where those bugs exist they are often of the form "stupid type where I have redefined & doesn't compile, while the standard technically days it should", where most users would never got them. Wrong answer or crash bugs in releases are extremely rare, although they could be rarer -- the test suite has less coverage than I would personally like.
The bug quality is higher than you might expect, because you have to register with bugzilla, and most bug reports are with development versions, as bugs are shaken out of new features. There are very few bugs in released versions, and where those bugs exist they are often of the form "stupid type where I have redefined & doesn't compile, while the standard technically days it should", where most users would never got them. Wrong answer or crash bugs in releases are extremely rare, although they could be rarer -- the test suite has less coverage than I would personally like.