agreed, having sane defaults for common use cases is a GOOD thing.
Just don't make the mistake of thinking that those common use cases are the only use cases.
I remember listening to you talk at some USENIX event a decade or so ago and talking about all the new things that were popping up on desktop systems (transparent terminal windows and similar IIRC) and you commented that when developing X you not only never considered such things, but if asked you would have said that it wasn't possible.
Because the mechanism was flexible enough, new things that the initial developers never imagined were possible.
It seems like a lot of people have forgotten that.
Ubuntu is the force that it is today, not because they were doing any hard technical things that nobody else was doing, but in large part because they were offering sane defaults (with some technical effort in automating configs and device detection) that nobody else was doing at the time.