I believe Morrus has given you THE reason for their business choice. It is a good one from their perspective. That's the only reason they need.
What? That sales of their
Pathfinder Core Rulebook would suffer?
I don't buy that. It seems like a stretch.
That implies that people are buying and playing Pathfinder rather than 5e because they want to play Pathfinder adventures but find conversion too hard.
Yeah... Nope. Just running Pathfinder is significantly harder and requires more prep than converting adventures to 5e.
Or it implies there's an audience that loves Paizo but is holding off switching to 5e because they want Paizo's permission & approval. Which seems even more unlikely…. Yeah, people are fans and like to support their team, but they're not likely to keep playing a game they're not enjoying just to support a company.
People buy the CRB because they
want to play Pathfinder. Not because they don't have options.
And, again, this would be a potential investment. Doing conversions of new adventures would encourage people to buy those, increasing sales of those products that—unlike the CRB—would still be trying to recoup their cost.
And it gets money from people who already swapped over to 5e and bought the CRB. I'm debating converting
Carrion Crown to 5e and running that sometime. But if I could just drop $10-20 and get a slick PDF from Paizo that did all the work for me, I would. Happily.
Further, I think folks are underestimating the backlash from the PF community. Rational or not, they would feel betrayed in a sense if Paizo made this move. Alienating the hardcore followers of their line is simply not worth the possible short term monetary gain.
I think you’re overestimating the number of Pathfinder & Paizo fans that are edition warriors. That’s a small, small subset of the audience typically localized to message boards.
Also, if the fans are that fickle and willing to abandon Paizo the SECOND they publish something for 5e, then they're probably not the most reliable fans. It’s not good to cater to an audience willing to blackmail you like that.
They’re not the people you want championing your game. Is that the kind of gamer you want representing your game in game stores? Being the face of your system to newcomers?
Paizo would be better off without fans like that.
Plus, this is also overlooking the many members of the Pathfinder community who reluctantly stopped buying Paizo products because they weren't selling anything they wanted. I loved giving my money to the company, because they were this great open, friendly, and accessible community that seemed focused on improving the industry. I'd love to buy more stuff from them, but I'm not a charity. I've bought too many gamebooks I'll never use (with a good four or five big $40 hardcovers from Paizo alone). But 5e Paizo adventures are a must-buy.