I'd guess it is a matter of priorities (do you want the safest, best-tested environment, or something less tested?).
However, assuming the source is easily bootstrappable, someone should try producing an unofficial port to Arm and Risc V. I'm sure it would reveal some security holes, even if it isn't appropriate (yet) for tails' target audience.
I'm so tired of seeing this argument. Most "big" open-source projects are well funded. Usually the reason they don't support <<obvious thing>> is poor leadership, not funding.
Over the past two years Tails has received 500k USD in bitcoin alone:
