Nick,
While I agree with some of your points--there are some I do not. With arrangers you "can" do more modern music--however, there are limitations, and even using current arrangers, there will be a noticable difference with modern styles done on a pro arranger and those done on modern synths.

when it comes to using acoustic voices--there were many times I felt the arranger department had the synth world beat "hands down". That's changed now because companies like Yamaha are putting the mega voices on the synths--and I wouldn't be surprised to find Super Articulation voices on the next MOtif That seems like the next logical step for Yamaha.

However, when it comes to "synth" sounds which are "huge" in modern music--well the synths take the cake here--they're synths, that's what they do. Also one part of modern music--be it dance, rap, hip hop, or whatever "absolutely must have" modern drum sounds. The drum sounds change "constantly" in these genres--as do the sounds.

I really wouldn't call it being lazy. Sure you can tweek the living crap out of an arranger, but you can only go so far with them because of the "sound set" and other limitations. Also these styles really work best in a "groove box" set up. The synths are working more like groove boxes now. Where you lay your killer tracks, then you start switching patterns live, change parts, grap a knob, and go nuts. Arrangers just aren't quite there yet for this.

Squeak