Are PhD degrees required to do machine learning research? Or can someone be completely self-taught and contribute to the field as much as those with PhDs?
While I don't do academic research, I spend a non-trivial amount of time reading papers and keeping abreast of new research that is relevant to my job. If the research seems relevant enough, I'll dig deeper and implement the research into a workable model. The software engineering portion really kicks in when I productionize this model and make it a usable product.
So in regards to your question, if you want to do fundamental, academic research then go for your PhD. For the kind of work I do currently, then it's more about the group you work with in industry.