5e's goal is to be a great compromise, and it's being pitched to a number of factions who are reluctant to compromise, and in some cases, have no incentive to compromise whatsoever.
Like
I said, you are only using part of the picture.
It is also being pitched to a number of factions who ARE willing to compromise. It is being pitched to a number of factions (or groups) who have numerous incentives to switch or adopt 5e wholesale.
It isn't just about getting the AD&Ders to play new D&D again, it is about getting as many people from as many factions as possible to play it.
If they made
4e supreme then it will only interest 4e people. And even then it will only interest a select number of 4e people who want to switch, because there is probably a margin of 4e that doesn't want to buy new books just because WotC says so.
If they made what they are proposing and attract 4e people, 3e people, 2e people, 1e people. People who have switched to D10 games, people who have quit, people who have started playing clones, or OGL stuff, or PF people, or whatever. Then if they do make a product that can attract a good percentage of people from all these factions, and more, then they will have more people than if they had just made 4e. It is a simple as that.
Is that to say that they will all be interested in compromising and using a game they don't like? Of course not.
But does it mean that they would be willing to try a system that can accommodate aspects of what they like from their preferred edition but in a new form, which happens to be supported by WotC? YES.
5e isn't about compromise. It is about making the best of what D&D has over the course of nearly 40 years of evolution. Not about making a game about the course of evolution for the past 5 years only. The more it resembles 4e, and only 4e, the more it WILL fail. It can't win by catering only to one group. It has to try and appeal to as many groups as possible.