Well, it is their choice...
But the justification given for it is retarded.
I mean if Dura had just said "I'm not translating any more because I got bored of it", that is one thing... and perfectly fine, I might add...
But what they're basically saying is "I'm not translating any more because I think everyone should be obligated to pay for an inferior paper copy, which I assume everyone has access to"... which is completely retarded.
I don't buy manga... generally. I've bought a few in the dim and distant past (ironically in a time when they were even more difficult to get hold of than now), and been given others (ended up with the first GON collection this way)... But they were almost always one-shots or independent stories because bookshops never had full series, often missing bits (like fuck I'd ever buy some pick-and-mix collection of incomplete content), and they were only ever the most popular series since who could be bothered to import American translations of Japanese manga to the UK? And given how inordinately expensive manga is here, anything on a larger scale was always beyond my pay-grade in the past.
These days I don't deal with physical books at all. For written fiction, I default to listening to audiobooks via Audible. The only reason I read manga at all is because it is easily accessible through my laptop. I wouldn't bother otherwise. Trying to handle with official licensed releases means dealing with lower accessibility, obscene costs, frequently lower quality, and is just an all-round bad time.
So basically if someone stops translating or... worse yet... redacts chapters they've already translated (a few manga have suffered this fate already)... all that happens on my end is that I don't read that manga...
Nobody is getting my money either way... because sites like this don't charge... and because the "licensed" hardcopy versions aren't worth it. Ironically if there were a site like this that charged for membership and guaranteed higher quality than the free stuff... I'd pay for it... but no... we're expected to go try and order bundles of printed low-quality paper off amazon for like £20 per chapter or whatever... Fuck that.
It isn't like the mangaka would give a shit about international sales anyway. How many content producers in Japan even give a single flying fuck about sales outside Japan? Not many.
So really... quit with the deranged excuses. If you don't want to translate any more because you're tired of it... just fuckin well say so. Or just vanish into the aether. Even dropping it and running without a single word to anyone is better than making up these excuses about licensed crap.