I'm no way an expert of marketing. I'm very far from knowing how the game industry works in terms of optimum release rate and strategies. So I only can talk as a customer. And I'll try with my approximative english to express what I believe in statements because I'm very far from having a coherent and structured vision about the whole problem.
1. If I want to sell a game (you must read edition, in case of an RPG) I can build up a good game and put it on the market. If it is well received I'll make money until the market will be filled. Then I can reissue it for new players and stabilize my output to the demand (this is far from easy and many companies fail in that producing too much copies).
2. sure I can produce accessories for that game (you must read adventures path, campaign settings in case of RPG) trying to sell more products and consolidate my ecosystem and/or fidelize my customers
3. If I want to sell another game (edition for RPG), I must be sure not to overlap with the previous (in case of RPG editions this is impossible) if I don't want to split my customer base and earn the same amount of money with two products instead of only one. This would be a suicide in terms of cost efficiency.
Said that, from my personal point of view, I've been playing all editions starting from BECMI/Rules Cyclopedia. I had accepted to move to AD&D2Ed because it were more pro in my vision. More options, more situations coded by rules, more class/race combinations etc etc. Obviously it were to much fragmented, to much dispersed in tons of material and I was a young guy, no internet no pdf and definitely no money to buy everything (consider also that the everything I was considering was Italian Language everything so a sub sub sub set of all the published material).
SO
I had accepted to move to 3rd edition hoping that it will be a fresh re-start and finally give me the possibility to follow the game from scratch, maintain me updated and evaluate all the materials as soon as it were published. I enjoyed 3rd very much but year by year it was difficult to stay updated and here again the same fragmentation of rules, the same enormous quantity of options and c'mon enough is enough. I buy every single product published for forgotten realms in 3rd edition and i remember that i was jumping straight to lore and that lore was the only thing that kept me from quit buying products.
BUT When WoTC released 3.5ed I fill myself joked. C'mon, are you trying to steal my money? Ok I can accept one edition totally uncompatible with the previous after many years but I have bought a game. Feel like my new car was perfectly functional, almost new but they suddenly changed the type of fuel in stations and only for marketing purposes assuming that I'm a cow to suck. They didn't love the game they sell. This was my mood, justified or not.
With this first false step in my relationship with WoTC, I was never impressed to see the coming of 4ed and I jump it with satisfaction. You will not have me!
Now I'm an happy customer of 5ed products. I buy them all cause in first instance now I can from the financial point of view, but more deep because I like the way they respect the game and the gamer stopping issuing crunch without sense. I like Adventure books with a lot of lore inside that are valuable even if you don't actually play the adventures. I like the effort to renew the campaign settings but maintaining FR traditional and not destroying it as per 4ed.
My two cents is that if WoTC respect the game saying "this is the game, 5ed, like it or not" and put the effort in producing quality lore/adventure material I can say that I can forgive all the false step made before.
In conclusion, now is time to produce wonderful adventure path. 1 at year but very good. Hire the best writers, ask to create plot to big names of fantasy like Sanderson or Sapkowski or Martin. Invest in quality with 1 adventure path at year that would be beatiful even only to read. I'm dreaming?