> Why is finding and filing a bug similar/the same as one you found elsewhere suddenly "bad practice"?
Because filling in bug reports against 200+ distributions is an immense waste of time, both for the reporter and the people doing triage on the 200+ bug trackers. Once you're able to reproduce the bug with an unpatched upstream, I think it's safe to consider all distributions to be suffering from the problem and filing a bug upstream should be the only thing you need to do.
Note that Fedora has a policy that all upstream bugs should be taken care of in the upstream bug tracker. That's why bugzilla.redhat.com has an UPSTREAM resolution and that's why this bug was closed with this resolution. The only thing filing it accomplished was wasting people's time.