It's a lot like shoplifting. Someone pays for the stolen merchandise--the honest consumer.
I know that Apple have high margins, but not with Mac OS X--yet. They have too many people dedicated to getting it going for it to really be profitable in a big way right now.
The server software should be tied to a serial number in the machine--just like the big guys have. You have that serial number as long as you keep the machine/O.S. combination current, even through upgrades.
It's really not a terrible thing to expect. Apple should protect themselves at least, on the server level. If they would go with something on the consumer level, it would have to be very clever and not so intrusive to make things go smoothly.
I want to be able to afford the software to use my machine, so paying a reasonable price is the only way to keep doing that. Everybody buy Mac OS X. Well, at least, if you have a machine that will run it. If you've got a Wintel machine, buy two copies of Mac OS X. 😀