The growing enmity between golfers who took the Saudi cash and those who stayed loyal to the established tours has burst back into the open ahead of the PGA Championship at Wentworth.
European Tour members like Ian Poulter, Sergio Garcia and Lee Westwood can play after their suspensions for playing in the inaugural event of the Saudi-backed breakaway were temporarily stayed on appeal.
American Talor Gooch and Mexico's Abraham Ancer are also in the field thanks to being in the world's top 60, but Horschel believes they are being "hypocritical" in chasing ranking points having never shown any interest in the event before.
"I honestly don't think that the American guys who haven't supported the Tour should be here," defending champion Billy Horschel said. "Abraham Ancer, Talor Gooch... you've never played this tournament, you've never supported the DP World Tour. Why are you here?
"You are here for one reason only and that's to try to get world ranking points because you don't have it (on LIV Golf).
"It's pretty hypocritical to come over here and play outside LIV when your big thing was to spend more time with family and want to play less golf.
"I wouldn't call Lee Westwood and Ian Poulter hypocrites because they never said they wanted to play less. The guys that have publicly stated they want to play less, those are the hypocrites."
Horschel believes that players were "naive" to believe that they would not be suspended by the PGA Tour for joining LIV and that some failed to adequately weigh up the pros and cons.
"Maybe those guys aren't smart enough to think on their own and maybe their agents gave them bad information" Horschel added.
"I know for a fact that certain agents just gave certain players bad information and some of those players are ticked (off) that they listened to their agents on that.
"Some of these agents led these guys down a bad road. They didn't give them the entire information and they didn't play devil's advocate the way they should have.
"We made a list. There was a lot of cons on that LIV Golf side and very few on the PGA Tour and DP World Tour. There's a lot more pros on that side."
The presence of the LIV players in the field has contributed to lower-ranked DP World Tour members missing out, with Rahm's friend Alfredo Garcia-Heredia currently the first reserve.
"There are many players that have been key for European Tour golf and the Ryder Cup that have a lot of collective years on the European Tour," Rahm said. "Them coming, I don't necessarily think it's a bad thing.
"What I don't understand is some players that have never shown any interest in the European Tour, have never shown any interest in playing this event, being given an opportunity just because they can get world ranking points and hopefully make majors next year.
"It does bug me that somebody who has played over 20 DP World events this year cannot be given the opportunity to play a flagship event because [of them].
"They don't know. They don't care. They don't know the history of this event."
Two-time major winner Martin Kaymer withdrew from the tournament last week, telling Golf Digest: "I don't need to go to a place where, feel-wise, you're not that welcome. They don't say it, but (it's there)."