This is from the Wikipedia entry on Hulk Hogan:
After purchasing the company from his father in 1982,
Vincent K. McMahon had plans to expand the territory into a nationwide promotion, and he handpicked Hulk Hogan to be the company's showpiece attraction due to his charisma and name recognition.
Yeah, I know it's Wikipedia

But it's consistent with other things I've read and heard over the years. Hogan was picked by VKM because of his charisma and ability to sell the WWF to a national audience as the face of the company.
Also, Hogan, at 6-foot-7 and around 300 pounds, was the right size for the big man prototype that McMahon reportedly has preferred for decades.
So with no Hulk Hogan, Vince McMahon's candidate has to have
- charisma
- good looks
- size
- the ability to sell the WWF to the nation, and to the world
- family and kid-friendly, because he's going to have to sell lots of merchandise
Who else could meet that criteria, at least in part?
- Andre the Giant
- Big John Studd
- Roddy Piper
- Ric Flair
- Bruiser Brody
- Kerry Von Erich
- Hacksaw Jim Duggan
- Randy Savage
All of them meet some of the criteria above, but none of them really meet all of it.
- Ric Flair has the charisma, but his party-with-the-ladies makes him family- and kid-UNfriendly.
- Randy Savage could pull it off, especially with his WWF good-guy persona, but I'm not convinced he could do as well as Hogan had.
- Kerry Von Erich has the look to be popular with the fans and wholesome sex appeal that doesn't negate his marketability to families and kids. But would he have been as personable as Hogan, and would his personal demons have consumed him in such a high-profile, high-pressure position?
- The knock against Piper is his (lack of) size, and also his personality isn't as attractive to moms and kids. He worked very well in the lead heel role.
- Studd, Andre and Brody were more attractions, and Brody in particular not only looked like a wild man, he went where the money was...and liked not to be tied down to any one promotion. Also, not as mom-friendly and kid-friendly as Hogan was.
Therefore, the closest guy of the aforementioned wrestlers to a Hogan-type I can think of is Hacksaw Jim Duggan. Size, charisma, looks, family-friendly, mom-friendly, doesn't scare average people off, all-American guy that the fans can rally behind. The only limits to Duggan's success would be how well he could handle the job.
And if
that didn't work...
Perhaps Vince throws money at Mr. T to be the face of the WWF.
Or, he decides that the face of the company has to be a smaller-sized guy (throwing the door wide open to the likes of a Ricky Steamboat)...
Or...waits for someone who fits his ideal criteria comes along, and is rewarded when Jim Hellwig comes along in 1987, and becomes mega successful as the Ultimate Warrior