One possibility could be that they actually never achieved product market fit: They went viral with their free offering, but those were just users not customers

One possibility could be that they actually never achieved product market fit: They went viral with their free offering, but those were just users not customers. 1. When it came time to pay, they actually didn't have many customers. 2. The price-points at which they were selling licenses at meant customers would need to be among the Fortune 5000: their sales cycles are long, complicated and expensive