Oppenheimer will be Rated R

No, I believe it’s because Matt Damon says the F word in it several times.

Which F word and whether it was scripted are both up for debate.

I'll admit, OP, I laughed.

Op, the bomb IS an F-bomb.

I think it’s going to bomb (pun intended).

Oppenheimer? Oppennasty!

R5 = Alma deBeers Oppenheimer

Because it's not about an atomic bomb, it's about a NUDE bomb!

So much ass eating for a historical war drama.

Robert Oppenheimer had communist affiliations. To the conservative minds of the 1940s and 50s, this meant that he must have been sexually depraved (think of the kind of take J Edgar Hoover would have had on him). So a sort of mythology has built up around the man, blowing all of his relationships, real or inferred, into anecdotes of degeneracy or immorality. This biopic will likely use some of that material in order to generate the kind of salacious interest that would warrant an R rating.

Here's Conservapedia's take on Oppenheimer (not that it is in any way accurate, but to give a taste of what some of the subject matter for this film might well entail):

I'm sure kids across the nation will be broken hearted at having to miss out on a talky, three-hour long WWII drama.

R10 The recent tv series "Manhattan" hinted around at making their Oppenheimer seem like a perv.