From my reading through of the document it seems like it would be very hard for any nation who hasn't hosted before or doesn't have massive stadia already sitting there to ever win the right host a RWC again. They also seem to have forgotten some of the aspects that made England 2015 a successful tournament, namely that not all the games were held in a few extremely large stadiums, and that the tournament was spread across the country to give a greater atmposphere in the host nation. Also South Africa would have very few of those stadiums at the required level if it wasn't for them hosting the FIFA World Cup in 2010 where there lack of existing grounds didn't seem to hinder their bid, and likewise for France with the 2016 Euros, which saw massive development work even though they had the Stadia from RWC2007 there. The aspects I would have thought we were obviously strongest in e.g. government support, security, legacy and vision and ease of transport for teams were areas where we saw little or no gains at all, and the areas where we were always going to be lacking like Venues and hosting experience counted massively against us. But here's to hoping that the next time a bid is being put forward that a redeveloped Sportsgrounds may be a part of it.

One of the widely touted advantages of the Irish bid was that we had never hosted it before (at least not alone or as the principal host) whereas the others had, but if you look at the assessment criteria, that wasn't taken into consideration. I suppose you could consider it an element of Vision and Hosting Concept, but that's still a small proportion of the overall score. (Maybe it's all explained on one of the 138 pages I didn't read.)
Based on those criteria, you'd imagine that if England had bid again, they probably would have got it. In fact if they find a good host, no reason the same union can't keep winning it every time.

VISION AND HOSTING CONCEPT 10%
TOURNAMENT, ORGANISATION AND SCHEDULE 5%
VENUES AND HOST CITIES 30%
TOURNAMENT INFRASTRUCTURE 20%
FINANCE, COMMERCIAL AND COMMITMENTS 35%

That said I never quite understood how we were such raging favourites for so long.
Dick Spring has been known to pull off the odd surprise on polling day though so it mightn't be over yet

Paris has the Olympics in 2024, and there was concern that this would overshadow the RWC, much as is happening in Japan. Personally I hope SA get it, that way we might have a chance with 2027. That said we'd need more than 5 fit for purpose stadiums (Croker, Lansdowne, Ravenhill, Thomond & Pairc Ui Chaoimh), a full transport link from Cork up to Derry, and to have nuked Buttevant, so I won't be holding my breadth.

In other Rugby news it appears that Ireland have gone from favourites to rank outsiders following the independent appraisal of the bids. It came to the conclusion that South Africa had the best bid. Now I could have accepted France as the best bid, but in no way can I see how South Africa ,a country that barely was able to get government support to even put forward their bid, has the best bid. I'm really disappointed at this decision and hope that even if it isn't us that gets the RWC that it doesn't go to them.