Do you want to have a lot of pictures with one of you missing or would you rather have a lot of photos where all of you are in the same picture in addition to the pictures you take?
That was the question I asked myself when I was debating. I decided it's worth it to have all of us be in the same photo and not rely on strangers to take a picture with our camera that would be non-fuzzy/crooked. Can't tell you how many photos I've had strangers take for me where one of us has a head cut off or it looks like we're standing on a hill. People like my DMIL are incapable of taking a photo that does not include their thumb or somehow making it fuzzy even with all the stabilizing technology.
The whole "do you want someone always to be missing" is something I never understood. If you take the picture yourself you are missing from the picture, that makes sense. But for any picture you could take advantage of Memory Maker with, you have someone to take the picture for you, a Disney photographer, so you're always in the picture.
I don't think that made sense, so I'll try again.
Situation 1 - I don't have Memory Maker and want to take a photo in a random location. No Disney Photographer, I have to miss being in the picture and take it myself. Having Memory Maker wouldn't have helped.
Situation 2 - I don't have Memory Maker and want to take a photo in a place with a Disney Photographer. I let them take my picture and attach it to my magic band. Then I hand them my camera and they take a picture with it. I'm still in the picture. Having Memory Maker would only allow me to have multiple pictures at this location, and this is where the value of Memory Maker is in.
My second last trip I got "Memory Maker", or whatever it was called then. Yes I got a few extra pictures at each location (one really nice one in AK with DD holding Tinkerbell in her hand) but really nothing else. I still had the Disney Photographer take pictures with my camera even though I had Memory Maker, as I heard sometimes they lose your photos. It wasn't worth it for us in the end, and we didn't get it on our last visit.
If Disney didn't allow their photographers to take pictures with your camera I would say Memory Maker would be on the borderline of "must have" depending on the family, it could go either way. The way it is now, nah.