Until the current crop of managers retire, Atlassian will still have business. Some don't know anything other than Jira, so will recommend it on corporate purchases.
There were zero issues with performance/reliability that caused the outage, they just deleted hundreds of customers data, and had to manually restore the data due to lack of automated restore scripts.
Reliability is measured from a customer's perspective, not from a geeky vendor-oriented perspective of a backend service. When the vendor deletes data, the vendor's reliability quotient decreases, because that data is no longer available to the customer.