You do not have to have a cumulative GPA of 3.5 or higher to be admitted into a masters or a Ph D. degree program. To put it VERY bluntly, you are an idiot if you do not earn a masters degree. If you fail either your oral or written qualifying examinations to become a Ph.D. candidate and even ONE person on your dissertation committee refuses to retest you, what are you going to do when you don't have a masters degree fall back on? Yes, I HAVE seen this happen TWICE to two 30 or more years ago.
I assume we are talking about the United States, not Canada, Europe Asia, Africa, Australia or Mexico or South America.
Earning a masters degree is 2 to 3 times as hard as a bachelors degree. A Ph. D. is 5 times as hard as a masters. You HAVE to be able to do library research, field work, , write and communicate well, and be be able to play mental.mulilevel chess of academic politics. Graduate students are pawns. You are competing with other graduate and undergraduate students as well as faculty members who. may be your age or younger than you are, and they are competing with each other for tenure. Politics in academia can be just as vicious as anything you have seen in Trump's campaigns or administration.