I think they made a conscious decision to not pay for the hardware and load balancing required for a launch-night explosion of users, knowing that that hardware/software purchase would then sit around unused as the logins spread out over the next day or two.

The backlash probably didn't hurt sales, and they didn't have to spend a ton of extra money on one-time-use hardware.

I played a ton of Defender and Circus Circus. Great games.