Because she is making divorce sound awesome!
Maybe it is for her and she is obviously making the best of her situation but I don't know anybody who would choose this.
I know people (myself included) who think divorce has been the best thing, whose lives are happier now, but even for the most amicable of splits it hasn't been completely plain sailing.
If I was talking to someone I hadn't seen for a while, I might be able to make mine sound a bit like that too.
My DD is with her dad 2.5 days a week - I get lots of me time yes, I see friends and spend time with my current partner but it actually took a lot of getting used to and I hate the fact she isn't with me all the time.
I used the extra time to advance my career too - mainly because I had to because the financial situation suddenly changed massively. But still, it's been rewarding in a way. I'd rather it had been when DD is a bit older though so I could reap the rewards of being with her while she is little too.
My Ex could perhaps tell friends that he is single at the moment because he is concentrating on himself and his career, I know he is lonely though. He hates the fact DD spends time with my new partner.
DD loves spending time with her dad and loves coming home to me. She does lots of fun things with both of us - more so than before because we are both wracked with guilt that we are not with her all the time.
She loves both her rooms and is very happy but she would rather stay in one place. She always says she doesn't want to go when it's time to go back to the other parents' and is always withdrawn slightly when she arrives as she needs a bit of time to settle in. She's back to normal after a short while but it's still a bit of a shame for her.
No situation is ideal, you make the best of it obviously, but don't decide to do this based on what your friend has said.