Maybe. BitBucket was also an acquisition so for some time I believe there was a lack of resource provided to them and there was a huge technical debt/integration effort required. At this very time, I don't know if Atlassian actually care much about BitBucket. They are probably more concerned about delivering Stash than BitBucket, my wild guess.

I was an active BB user a couple years ago, and the project I worked on would hg clone from BB many times a day so I would be the first one to notice a 503 or whatever error coming from their service. Typically I would see one or two outage per month, some last a few minutes, some last several hours. Most of the time the outage impacted git/hg checkout, so I think that was their technical bottleneck.