No, he didn't come out of nowhere and I don't buy anything labeled "Trump" because I've watched the guy for 30 years. I'd rather he was considered for Chief Trade Negotiator or SecState than President because at least I'd have good faith the US would come out on top in trade and diplomatic negotiations but he's the only candidate available now to avoid aClintonRodham presidency which would be an unmitigated disaster. He IS a bit of a wildcard which is why the establishment Republicans are STILL fighting him. He's hardly conservative but he's also nowhere near as corrupt as Hillary and is definitely a lot more competent at running large organizations. He's pretty bad at politics but that's actually a positive IMO.
A vote for Johnson or Stein may as well be a vote for Rodham, especially with the Leftists in the press eager to bolster her and the Democrats by shading their reporting (of course, that's nothing new ... the mainstream press has been doing this since Reagan, it's just gotten worse and more blatant in recent years).