Like a lot of fads in IT, Big Data sounded like "if you have a lot of data you can monetize it" so companies threw 7+ figures at the technology and then realised that you can have too much data to know what to do with and couldn't really monetize it (obviously some did/still do). Even at a simple level, working at a data collection company, it is very clear that lots of people want to collect as much as possible only then to do precisely nothing useful with the results.

Then Machine Learning comes along and these same people think that means that you can just feed the beast with your big data and it will be clever enough to tell you what you want to know and then the same companies will realise that they still don't have the skills to work out what to tell the ML algorithm to do.