I appreciate your comments. We've thought a lot about this, and we've discussed it directly with many users, and our current model seems to work the best for the most people.
I can't really get into too much depth here about our business strategy, but you should keep in mind that your situation is unique -- most people only have one computer, or only need to run Magic on one computer. If we allowed multiple installs per user, we'd have to raise the price, and that would be a much higher barrier to entry for the average customer. We want Magic to be a creative tool that almost anyone can afford.
It's nice of you to think of Magic and Ableton as comparable, but remember that Ableton costs much more than Magic -- Ableton's "medium-priced" version is almost 6 times more expensive than Magic's high-end version! And Ableton's "high-end" version is almost 10 times more expensive than Magic. When you are charging many many hundreds of dollars, it's a lot easier to offer multiple installs.
Of course, if you want to give us more money, we'd be happy to offer you more licenses

. In some sense, our current licensing model does ask advanced/professional users to pay more; but if you look around, you will see that a lot of software works this way. Further, most of our pro users tell us that Magic is still a good value for them, even when purchasing multiple licenses.
If there's some program out there that you think has comparable features to Magic, allows for unrestricted commercial use, and is approximately the same price, but allows multiple installs, please let me know and I'll take a look.