If we're being honest, it's pretty stupid. They just took Max and made it sound like a last name. I heard of a poor little kid with this name, and at first I couldn't believe my eyes when I saw it written out. Please, just go with Maxim.
Anything can become a name nowadays. Whether it be a literal word, or an elaboration on a classic considerably short name with a modern twist. Needless to say I’m unimpressed.
...If you wanna elaborate on Max, just name your child Maxim or Maximilian? Why THIS? I don't understand. Guys, you are not naming sims. You are naming PEOPLE who will have to live with this name. Please, think of your child's future.