Mike,
While generally, I'd agree with you, and to a certain point I still do, tractors can be a different can of worms. You can have too big of a tractor, while a larger, faster PC will always do smaller tasks, this isn't always true for a tractor.
The BX vs 7500 is a perfect example of my point. I have a ditch in the front of my home that I tried a 7500 with...it wanted to tip over when I started to use it, while the BX handles it just fine. Another....mowing in tight areas; the BX's smaller profile fits better, and is nicer to a manicured lawn. Another: Fitting the tractor inside sheds, as not everyone can afford to build a garage for their tractor.
All that being said, it is still wise to consider a larger tractor if you might need it, but remember that it can have a down side as well. In my situation, I might have liked a 2410, but it was too big for my application, as was the 7500.