Personally, I use Garageband to record my music for some purposes.
But before the recording can begin, I would have already written my song on with a piano or a guitar... So computer isn't everything. Know nuts about music, computers can't help you. So, one still need to learn how chords flow and stuffs...
So i would say, technology helps me to simulate how a band would play the new song i've written and also allow me to experiment with different style/moods/genre to present the newly written song... I don't need to find a full crew and a studio to do a recording.
And let say i'm doing a informal demo, i think computer is good enough.
my 2 cents
IT cannot replace music - IT is just an interface, a help, a robotic arm but not the experiment, etc. (if you watch ironman, u'll understand what i mean by robotic arm)
ADD ON:
Sampling clips and Apple Loops (they call it) can only do so much.
I tried recording my song with those loops. They sound fine (musically) but boring - really.
I realised I need to get up from my lazy bones to plug my guitar or midi controller in to do some stuffs which the loops can never do.
Loops can help, definitely, yet relying on them to do your music, that's insane! Oh come on...we don't all write technos and trance only, do we? (no offense to the genres

peace)