This has to be the most common (false) assumption statement going around. The Note 5 came out 8/21/15. The Note 7 came out 1 year later, 8/19/16. Phones are on a yearly cycle. They didn't rush this anymore than any other manufacturer rushed any phone over the last 10 years to get it out 1 year after the last one. We all can try to assume, and act like we know why there was a quality control failure, but you are just guessing unless you actually work for Samsung quality control and know the reason ..
Stuff happens, and the way people - or companies in this case - respond is what really matters. Everyone can have their own opinion about how they responded of course. Mine is that given the enormous scale, the litany of carriers, countries, laws, and the entire manufacturing chain to navigate replacements, Samsung did just a tremendous job so far. I applaud Samsung for having my issue fixed in less than 3 weeks from when the problem was announced. It's not 3 weeks, and I have a great new working phone for this unprecedented event. Think about that at a scale of millions with a broken phone..
Many aspects of an event like this can be frustrating, scary, and confusing. It's never happened before all. This recall was NEVER going to be clear and easy, in case anyone thought otherwise. I think a lot of folks need to gain a bit of perspective here ... Just my 2 cents ..