After I got fed up with the inconvenience and discomfort of carrying around heavy, bulky SLR gear for general photography a few years ago I bought an S90. These S class cameras are so small you carry them around effortlessly and, as you say, they are capable of good images ... in the right conditions.
Outdoors in good light - like your samples - there is no problem. However, indoors and when the light starts to fade a little it is a different story. I took some great poses of my kids, but when I attempted to produce largish prints the image quality just wasn't there. This happened a number of times and it started to get frustrating.
I then switched to the EOS M. The system was bigger and heavier than the S90, but the APS-C sensor and some good EF-M lenses fixed the IQ problems I had experienced with the S90. It was still a lot smaller than a DSLR system. I could also use all of my EF and EF-S lenses with the addition of an EOS M to EF converter.
The EOS M system isn't without its frustrations. In most situations it is OK, but sometimes the AF won't do what I want it to do, there is a limited range of EF-M lenses, and Canon's marketing strategy with this system up to now has been a joke.
I'm on the fence now whether to continue with EOS M or to go with a small SLR and pancake lenses. The rumours here about a possible M4 and SL2 both interest me.
But yes, I basically agree with you. If you understand the limitations of these cameras they can be very handy and they are absolutely no hassle at all to carry around because of their small size and weight.
Here's a write up of my S90 that I did when I was using it as my every day walkaround camera. It includes sample images and some of my thoughts about the camera.http://phil.uk.net/photography/canon_powershot_S90.html