Yes, but even there the 50% seems too much. I can see people submit that much bugs in cutting edge communities (where there are still a lot of new bugs to submit), but when you work with something stable you rarely ever need to do so. There is huge amount of positions where people successfully use what exists.
Plus, calling bug submissions as open source contribution is a stretch. You would not call "contributing to close source" when someone reports a bug to a company.
Plus, calling bug submissions as open source contribution is a stretch. You would not call "contributing to close source" when someone reports a bug to a company.