We do coordinating, but not matching. I just had pics of the kids done, DD1 wore a red shirt and a red skirt. DD2 wore a red sweater, a black skirt and black/red snowflake tights. DS wore khaki pants, a red turtleneck with a gray vest. I took the kids myself and wasn't intending to be in the photo, but I ended up being in one anyway since the 2-yo would not pose without sitting on my lap. I wore a gray sweater and black pants (not intending to be in the photo), but it turned out really well.
I think one problem with matchy stuff is that it's pretty hard for the exact same (or similar) outfit to look good on different people...who all have slightly different skin tones, different shapes, etc. I also think if the focus is on matching outfits, then there will be less focus on making sure that each member is wearing clothes that look good or are flattering with their skin tone, hair color, and body shape.
Even my kids, while they look cute in anything, they definitely look cuter in certain colors or styles or cuts of clothing. When we coordinate, we make sure everyone goes together (same general colors), while still making sure each individual is wearing clothes that suit their particular skin/hair color and body type.