Are you trying to start WW3?
I use both but W10 on several machines but W10 is the main OS I use. Very happy with it and W7 seems a bit clunky after using 10 but it really is a matter of what you get used to - the devil you know. Both will do the job.
I've turned off the amount of "tracking" it does but other things track you anyway One thing some people don't like is that W10 updates itself whether you like it or not. This can be annoying at times but IMO it is the fault of the people who never updated their computers which caused a lot of virus issues to be spread even though patches had been released to stop them.