None of the mirrorless cameras are compact with anything other than a pancake lens on them. It's a segment I don't quite understand, and I think a lot of canon users are the same when it comes to the M.
It does make sense if you have a little kit limited to about 2 or 3 small lenses that'll fit in a tiny bag and allows 'real' photography none the less. A nice quality alternative to a DSLR that you can take on almost any occasion where you don't want to bring the big SLR, or just want to shoot some casual photo's. The 'M' does that, and so do its rivals.
I must say such a mirrorless kit makes more sense when you compare the size of the system to a kit consisting of (semi) pro bodies and lenses rather than a little XXX(x)D with a mega-zoom lens. But that suits a different target audience IMHO.
I've a tiny 2-lens selection for my Nex-6 at the moment: the Sony E PZ 16-50 mm F3.5-5.6 OSS and the Sigma 30mm F2.8 EX DN. This combination will squeeze into a Lowepro Compact Courier 70, External Dimensions: 16.5 x 8 x 20.5 cm (6.50 x 3.15 x 8.07 in). I've no real ambition to use tele-lenses on this kit. The EVF however good it is, is a little too detached for fast work and the relatively fast AF on the Nex-6 is slow compared to a good DSLR. I do have a NEX-FD adapter though that allows me to use some old FD stuff I have, i.e. 70-210 F/4 FDn and 135 mm f/2.5 FL. The latter I still have to give a try.