The problem isn't support for the ARM architecture in general, it's the support for this particular board.
Other boards like the Raspberry Pi and many boards based on Rockchip SoCs have most of the necessary support mainlined, so the experience is quite painless. Many are starting to get support for UEFI as well.
Often an outright mediocre software development culture generally, that sees software as a pure cost centre, in fact. The "product" is seem to be the chip, the software "just" a side show (or worse, a channel by which their IP could leak).
The Rockchip stuff is better, but still has similar problems.
These companies need to learn that their hardware will be adopted more aggressively for products if the experience of integrating with it isn't sub-par.