I always thought it was strange that people went through the inconveniences of plugging a mouse into their laptop when there was a trackpad right there until I had to use a Windows system and saw just how bad it was.
It's also illegal to work on a laptop, without external peripherals and monitor, so you need a pointing device anyway.
I agree with this, but intentionally choosing a trackpad to put on your desk is just accepting a portion of this hell, in my opinion. The trackpad is an RSI torture device to me, because of the way you have to hold the muscles in the back of your hand tense so all but one finger is a little higher than the others.
It's great that we have options, so that people can pick what works for them. It is a little sad that Apple is pretty much the only option for an "external" trackpad though.