There’s a difference between liked/loved and famous. Frank was more popular, AJ is a lot, lot more famous.
Old Wembley wasn't a great venue for boxing. The stands were much further away from the pitch in those days (especially behind the goal mouths), and because the first tier was so flat (each row was barely higher than the row in front), the 2nd tier which was more horizontal seemed like miles away from the pitch, because it was so far back. So you have to make a decision, put the ring in the centre circle and give almost everyone a diabolical view, or move the ring closer to one stand, so that they get a good view, and don't sell tickets for the rest of the stadium. Even England matches were getting really poor attendances at this time (except for the really big matches), in the build up to Euro 96, the attendances were often around the 40,000 mark, and would have been even lower had they not been practically giving away tickets to school kids in the North West London area. It was an old decaying stadium, not designed for boxing, but it still had a lot of prestige and was world famous... they probably could have picked a better venue, but it's Wembley init.