Why did they actually introduce measures and what are its main functions?
Because spammers could create many many accounts and spam with them to gain higher ranks and activity.
With merit its impossible because you need quality posts not spam posts.
One problem with that is, people should reward quality posts which is not always the case because they don't know what merit is here or are just lazy.
I think merit is too scarce.
I want to merit many posts that really deserve it, but I have so few...
Most posts that deserve merit don´t get it. And sometimes a useless pots get 40, 30 merit just because is a friend of other legendary people...