I agree with other posters who have mentioned WotC's new strategy.
I don't honestly think WotC will ever, as long as they keep drawing in new players, remove 5e from the market.
They simply don't yet know whether or not they'll lose players by performing another "edition switch".
As long as ideas for 5e splatbooks continue to be pumped out, and a D&D book of any kind stays within the top 100 books on Amazon or whatever, WotC will recognize that their new player base is more willing to collect 5e splatbooks than switch to a new edition.
The most depressing thing about this is that 5e is already starting to produce ludicrously broken and unreasonably weak character options, and the designers outright refuse to recognize them as the pressing issues that they are.
Consider the Yuan-Ti Pureblood, and unreasonably powerful race. It was made in VGtM, the first 5e splatbook, which also contained the unreasonably weak Orc and Kobold races.
Consider the Ranger, which has since been revised. However, the revised ranger has not been released to the non-unearthed-arcana-reading public, which is stuck with the ordinary ranger.
There are already strictly better and strictly worse archetypes for more than one class.
I do love 5e, I actually think it's the most balanced edition yet, but it certainly isn't willing to admit (well, it's designers aren't willing to admit) its obvious flaws.
Though, I do have to thank Mearls for acknowledging that bonus actions are broken.