Sure - I could. But that's extra devices and usually extra power points at those locations (esp if you want any POE - I doubt there will ever be a switch that can be powered by, AND deliver POE at the same time). So it's extra devices to buy and support and manage which is why I decided against it. Having the extra ports doesn't stop me doing it in the future either.
The flip side of course is that a failure in one of the big switches takes a LOT of things offline and it's more expensive to replace. Not the VM cluster or servers - but about half the other devices (e.g. one of the WAPs, half the desktop points etc).