Maybe arrogance was the wrong word.
They're biggest issue with the LIV series is that it will reflect badly on the PGA with sponsorships etc.
Between the USPGA and DP Tour the world is neatly divided up thanks very much.
As always, it comes down to money. Saudi has more, they are worried.
They were sure that the threats of bans would mean nobody would sign up. Of course players signed up, and more will.
They need to come to an agreement with the LIV tour pretty quick on a shared calendar before they lose all their 'stars' forever.
If they stick to their guns the Ryder Cup will soon be contested by none of the world's top players, they'll all be barred from entry.