A Yokozuna title reign was inevitable. The guy looked the part of a monster heel, acted the part to perfection, was incredibly mobile for his size, got good heat for a variety of reasons (size, "nationality", Fuji, etc.), and occasionally looked "beatable." Added to which, how he didn't regularly kill people with his Banzai Drop finisher astonishes me to this day.
I agree that Yoko dropping the belt to Hogan right after winning it from Hart could be conceived as shoddy booking and damaging to Bret. However, this was Wrestlemania and more importantly, early 90's Wrestlemania. The concept of a heel walking out with the title wasn't fully explored yet and hadn't been done prior. Hogan was still huge and him coming in, "defending" America, and righting a wrong was still very much present in the wrestling audience psyche. In short, Yoko beating Bret, then losing in record time to Hogan made sense at this point in wrestling history.
Yokozuna as a character/concept is still something that could be relevant today, provided some minor tweaks are employed. Problem is, the opportunity for Vince and company to find such a unique performer is slim. Yoko really did have it all and although quite expected, his early death was still a blow to wrestling in general. I think one would have a hard time finding a "giant" that came after Yoko that was so effective in putting the entire persona of a monster heel over.
Despite the somewhat short span of his career, Yoko should get a Hall of Fame induction, if not near-top billing within the next few years.