I think it's too early for people to say it's dying. Right now it seems to be doing very well but we don't know if it will have long term adoption. It may never be mainstream but as long as it has a niche then it can still gain value.
Exactly its not true that bitcoin is dying. Bitcoin with its growing potential on the path of being mainstream. At the same more users were adopting it which won't allow bitcoin to die soon.
The long-term potential of Bitcoin definitely exists in an investment capacity, but the infrastructure behind Bitcoin might be a bit too small right now for global-scale adoption, primarily because of the time it takes to confirm a transaction. For online payments it isn't bad, but for day-to-day transactions there might have to be some services constructed to make small and simple transactions more viable.