It was back then..we don't even support them in our framework anymore. Most folks use VAEs and GANs for generative models now. In general, they are just more stable.
How about DBN? It is also a generative model but why now rarely used?
ML researchers following trends, like doing end-to-end CNN for whatever problems, and using this LSTM and that GRU and that latest architectures; in similar fashion like web devs picking and dropping javascript frameworks.
