Who is to say that discarding 4E and its fans entirely and going back to 3.5E isn't equally suicidal? 4E is over, and 5E is coming, but it doesn't mean that 4E needs to be purged so that things can go back to how they should be, and that isn't what 5E is advertising.
Who says they are going back to 3rd edition? Pathfinder has that covered so it would be suicide if Wizards even tried that. 4th edition has gotten a reaction that has never been seen before in D&D. While they won't be going back to 3rd edition I bet you they would go back to more of a 3rd edition type game than they would a 4th. Not saying that as a fact but as a personal opinion.
The odds are stacked against 4th edition and in the world of speculators and capitalism that is a big no no.