Mozilla's popularity has gone from almost zero to double digits, so they have had to deal with a lot of sudden attention. Since Mozilla has become popular, people have been looking for more vulnerabilities.
Quotes about mozillas (2 Quotes)
Given Mozilla's open and transparent approach, we are very detailed on how we publish our vulnerability reports, and we list each vulnerability separately. Other vendors don't. Other vendors often combine multiple vulnerabilities, for instance, into one security bulletin.