[Lil' Lavery]

Echoing an eariler post, FIRST does not create the Vex product, only the FIRST Vex Challenge game. Just like LEGO makes the Mindstorm kit, Innovation First produces the Vex kit.
Vex is the "middle-ground" between FLL and FRC. I have seen multiple posts concerning how much harder it is to "tinker" around, deconstruct, and reconstruct a Vex robot than a Lego one. Coming from an FRC perspective, I found FVC bots to be much simpler to tinker and play around with. In vex it can take a couple hours to maybe a day depending on how involved and how many "custom" parts you have to make to create a robot feature, while in FRC it would take much much longer than that. An FVC design problem can typically be ironed out in a single build meeting, maybe two, while in FRC, if you design fails, you're often up the creek without a paddle, and you have to abandon that feature.
With the Vex kit, while there are limits to what you can do with the "stock" material, it presents a whole new feature to the educational and creative process behind creating a final product. While with Legos you can tinker, build, re-build, etc all with stock pieces, with Vex you have to do substantially more designing beforehand, and you are introduced to many more mechanical and fabrication issues. You have to decide, how, where, and actually manufacture custom pieces from the stock pieces to pursue more ambitious designs. I think that was an intentional, and if not then still advantageous, feature.
Also keep in mind the squarebot was meant to be what it is, not something else. It was meant to be a simple, robust platform for a customer to get a feel for the Vex kit when they first purchase it. It may be hard to re-design, but that's because it wasn't meant to be re-designed. It would probably be alot simpler to actually build a custom platform from the starter kit if you wished to tinker around and play with gear ratios, etc more.