Not all projects need complex data representations. I would suggest that few projects need a complex data representation rather they need an appropriate one. As to views, transactions, and stored procedures consider a large open messaging system like Twitter. While a traditional database could help with the users profiles and settings giving that up for a significant increase in speed might be a great trade off for them. Or they could mix several database systems using the best tool for the job.

The idea that all databases need all features is a mistake, once one free open source project has everything and the kitchen sink it's time to start solving other problems.