I believe you needed a MS account in Windows 10 to buy apps. Others were free to use.
The main advantage, for multi device users, is the sync ability with an MS account. I confess I use this a great deal across my devices - those already running and new installations.
There is talk on the web regarding the better login security with a local account. I don' really see that.. I am sure, if a hacker were sufficiently interested, he could hack into a local user computer far easier than tackling the Microsoft servers.
fwiw. I had a quicky into the store and picked on Minecraft for windows 10.. This needs to be purchased, ie. A Microsoft account. It is freely available on the Internet - no mention of an account required.
I fully support your sentiments. I guess it is a very personal decision for each individual.