I have not been that active on ENWorld for a while now. 2013 was a...challenging...year. I've mostly missed or sat out many of the RPG worlds trials and travails. Though my group and I have downloaded some of the playtest packets and ran a few sessions, we haven't been discussing and debating it hotly. We all returned to gaming after a long absence when we tried 3E, found our bliss rekindled and have gamed regularly since (though in recent years the frequency has decreased). We moved to 3.5, then to 4E. We purchased some of the Essentials material. We have tried 5E. It's is very likely...nay, almost certain, that we shall move to D&DN/5E/whatever it eventually is called when it is commercially available.
Some of my players never fully cottoned to 4E, though they played it. A few of my players are entirely neutral on the affair: they considered the group of players and setting specifics far more important than specific rules. Thief? Thief/Acrobat? Rogue? Shadowdancer? Whatever. Can she pick the lock or not?
Patterns repeat. When I moved from Basic to Advanced. When 2E arrived. When 3E spawned THIS site, which I found when trying to figure out Attacks of Opportunity. When 3.5 came out and when 4E was marketed. So when I see a discussion of how 5E is...'in trouble'. I tend not to lend it much credence. D&D fans love change and hate it in equal measure. Only Hasbro and WotC know what they intend, how successful any of their previous efforts were, how successful their current efforts are and how successful they hope their next ventures to be. I think the OP has decided that 5E is in trouble and may be experiencing a little confirmation bias.
Let us be frank: D&D is THE role-playing brand to the general public. It just is. Pathfinder is a fine game and certainly no slouch. It is, honestly, the ONLY brand one finds if they go to a Barnes & Nobles or Target besides D&D. But the further afield you go, the less recognition you get. Toys 'r Us carries D&D Kreo, D&D videos, D&D board games, D&D action figures and so on. Pathfinder has some of those, but they're much more niche items. D&D is too big and well known a brand for 5E to be a failure, but it is possible for it to under-perform. That is hardly the same thing as failing.
Now, what does the OP mean, exactly, by 'In Trouble'? That's a question that I think is worth examining. I think we can all agree that there is no danger that WotC will suddenly lose their funding and be unable to market, print and release the game. So what trouble is it 'in'? I'm going to assume that the trouble is that it won't sell well, but that particular claim has been made multiple times and while we don't have access to the sales figures of private companies, we do have some of the financial data Mistwell has been referencing from investor calls and annual reports. We know that they are owned by one of the largest toy/game manufacturers in the world and that their single biggest competitor is probably a quarter of their size. And based on that data, we know that Hasbro has faith in the brand and that it has steadily increased over the last year or so.
I think it's safe to say that 5E has a plug-in audience of a certain size. Likewise, I think that a steady but not overly aggressive schedule of releases should be able to sustain a certain level of sales...one that WotC and Hasbro should have a decent handle on. Part of the issue is determining how many people will purchase the game past buying the initial core books and how many will convert to full time players (and, of course, how many new players enter the fold). As with previous transitions, there is a sort of amnesia that seems to occur prior to the release among many fans (or they may be too new to the hobby or just too young to have been there) about the last one. I have had posters indicate to me that there was never the kind of edition wars from 3.5E versus 4E engendered, which led me to wonder where they were when 2E came out or if they read the posts prior to 3E's release or if they remember the vitriol aimed at WotC for daring to release 3.5 so soon after 3E.
If the argument is that D&DN will be a failure unless it becomes the unchallenged master of the table...well, I'm not sure that it will ever happen, again. With the rise of so many game systems (especially F2P online MMOs), it's very hard to imagine that D&D will EVER rise to the level of zeitgeist it once enjoyed. And that's OK, IMHO. [side note: the idea that D&D needs to be made 'easier' to appeal to new gamers is, to me, ridiculous on it's face. A quick glance at wikis for online games like WoW, Warframe, ST: The Old Republic, Minecraft, Animal Crossing, Monster Hunter and dozens of other games indicate many gamers LOVE complexity...what they may or may not like is a totally offline gaming experience].
