There must be progress.
But frequently the best path forward is to admit your mistakes, go back and find a better path from where you once were.
I actually think a goal of targeting MMO players and Card game players *IS* as bad goal. You have to know who your market really is and wishful thinking for a bigger potential is just bad planning.
No one is calling for "stagnation". But there are things worse than stagnation and wandering off the path can be one of those things.
Dead ends or overly-fiddly bits or new problems are to be expected in design, and I agree that's when you return to your original aim and try again, more or less the process of making a practical, functional rules system. This is kind of where I see 4e right now. They're in a position to rework the weak points of the system, but there isn't enough cause, in my opinion, to dump the majority of it in favor of different design principles in an new edition, nor is it productive to reverse design principles established at the outset and seek the answers in older rules. It must be a forward process, and if it looks less like the D&D rules of the past, so be it.
Targeting MMO and CCG players is a fine goal, but I don't think it was limited to those two segments in regards to new players, I just think they've failed, thus far, to return to a wider public consciousness, and that requires good video games (here's hoping for Neverwinter- or better yet, pick a hungry, young studio and announce Baldur's Gate 3 for a spike in game press) and a Nentir Vale CN animated series, but I digress...
They never forgot their core market, though, to say those who play 4e or would play 4e. In fact, they're doing more now than I recall in my gaming past to reach out to me and my friends (gamers and non gamers), between Encounters and the upcoming Lair Assault, both of which offer me easy ways to introduce the game without having to do anything but show up, and which are way more accessible and constant than LFR ever was in my experience.
Not only that, these programs have garnered the attention of adjacent markets, for instance my Encounters program is run in a comic book and game shop, and we've drawn in comic readers as well as traditional hobbyists. Come to think, the shop also holds a number of Yugi-Oh, Pokemon and Magic tournaments, and they too have been reeled into the culture (and me back into Magic after a long lapse- Commander format is awesome). Will all of them stay with it, no, probably not, but there is exposure and a way for anyone to walk off the streets Wednesdays (and Lair Assault can be run any day of the week) to game.
For all the good I believe WotC have done, I by no means believe they've handled everything perfectly, or that the rules system doesn't need work. They didn't, and it does, but I kind of embrace the refining process and discovery. It feels exciting, you know, taking the game new places. And I've said this before, but it's a beautiful thing that as they do this, the other editions are always there for people, and all of them are supported.
I feel I've gotten way off topic. Sorry about that.
Speaking to your last point, though, getting lost can be frustrating, confusing, messy, ugly, yes, but if they keep pressing through the unknown, cutting through the doubts, moving forward into new mechanics, new settings and fluff, digital frontiers, instead of trying to retrace their steps to get back where they started, I believe the destination is just over the next hill. It's not design for design's sake, it's design for the game's sake, for our sake.
Also, I tend to favor the bold designers willing to try new things, to let the historical iterations of the game be what they are, and find new paths. You know, WotC are almost like path-finders...