Gained another players Achievements

I had never visited the end until Saturday the 7/10/17, but now it shows in my achievements I gained this in 2015. I have now gain a number of another players achievements, that date before I started playing on Windows 10 edition. They on the otherhand have been playing pocket edition far longer than I.

Personally I have no interest, nor do I see the point of them, but I now have aquired several which I have not earned, simply because I am playing on realms with other players.