Even with a slick gui, Fractal wouldn't come close to dominating the market for two reasons:
1. Limited production runs - Fractal products often go on a waitlist, presumably because each production run is quite small, so as to not tie up too much capital in stock.
2. Lack of a proper dealer network - you can't walk into a store to try and buy Fractal products.
IMO, both of these are part of the same problem - with a dealer/distributor network holding stock they've paid for, Fractal can increase the size of their production runs and perhaps achieve more economies of scale, but they'd also need to factor in a dealer markup, so prices would probably have to increase quite significantly (see G66 prices vs Fractal direct).