There are so many answers I could give you but I will only give you a couple.
There might a lot of undulations in the green and hitting a 60 degree wedge and not hitting good and wind up hitting it into one of the undulations, the ball will literally stop after it lands and roll backwards or if you hit it onto the top of one of the undulations it could roll more than you want it to.
You really have to have the touch around greens to use a 60 degree wedge.
Being a novice like yourself, the higher irons would work better for you but it takes a lot of practice and knowing how the greens roll.
Even though I consider myself a pretty good golfer, I use the higher irons around greens regularly. To me, it just seems like a safer shot unless there is something in my line to the hole.