Well, there was room for the tower where you're supposed to put your feet. But there wasn't enough room for both. But there was nowhere else to put the tower if I wanted to use the desk, so I put it down there.
Like I said, I just had no choice but to pop my feet on top of the computer tower, too.
These days, I have a cheap desk which, at the very least, allows me to keep my computer away from my desk! Now I sit cross-legged at my desk with my keyboard on my lap. XD;