Just how many options does 1 need in a 2 way bookshelf design?

I feel the same way about cheese.  There's cheddar and sharp cheddar.  What more can the world really need?

Erik must enjoy a small 2-way bookshelf speaker while drinking his warm Miller Lite and eating cheddar and wonderbread sandwiches.

Welcome to capitalism, bro. It's not about rationality, it's about "choice." The landfills and deforested landscapes can testify.

Personally, I'd like more acoustic suspension choices.

{Personally, I'd like more acoustic suspension choices} would require larger cabinets and today small is in, cheap to build, cheap to ship from China, easy to stock, and high profits on sales. They did a great job of selling small to the general public after all tech should be more compact not larger. That bumps into the laws of physics when building a device to produce a soundwave, sound waves didn't get smaller.