I think that has more to do with the people who use the sequencers.  I
have been using Logic from Emagic for years (and even when it was called
Creator/Notator) and have been able to do other things with it than what
you list.  Because the PC implementation of Logic didn't work very well
for me, I had to give it up, which I regret because it had some features
that I do miss in my current sequencer.  A decent sequencer will let you
change the time signature during the piece or, if you don't want to use
that you can arrange your events anyway you want in time, which is nice
for minimal music.

Job van Zuijlen

Josep M Comajuncosas wrote:
> 
> 
> Come on, with those pro-sequencers you cannot go further than recreating some plastified
> classical or jazz arrangements or derive to some tonal, 4/4 based techno stuff (techno,
> jungle, drum&bass, etc. all the same for me). I rarely use them (neither MIDI lately) in my
> music. If "real" music = music people dance at the disco/ music you  hear at the tube
> stations, maybe I´ll agree with you, but that is not certainly an extremely creative
> challenge IMHO.