That’s a bunch of editions, but I suppose we can cut that down to 5 if we take their mobile platform out, which isn’t terrible because in reality you only have 2 new editions. Education and IoT Core which don’t sound terrible. Obviously the average consumer will only need to worry about 2 editions - Home and Pro. The enterprise is clearly their business model (Both the WIn10 + Mobile variant). The Education will be directed towards schools, colleges, university’s and again not the average consumer. The IoT core would again be something directed towards tech business who’s business is, as you put it dumb terminals, etc.
In reality, this is actually a better layout then Windows 8, Windows 7 and WIndows Vista.
Windows Vista and 7, the consumers had to decide between Starter, Home Basic, Home Premium, Professional, and Ultimate. The Enterprise editions I don’t think were sold commercially in stores.
Windows 8 was better in the sense that you just had to decide between Windows 8 and Windows 8 Pro. Again the Enterprise edition I don’t think was commercially available. The one big issue with Windows 8 was RT as this confused the hell out of the average consumer. Thankfully it was only on their low end surface tablets and was not an option for the average consumer to purchase it for their own desktop.
So all that said, again the average consumer now only has to worry about Windows 10 Home and Windows 10 Pro which is pretty straightforward.