There seems to be a heavy trend in recent years towards all-in-one authoring tools. (unity, blender, unreal, etc)
The trend may have leaned this way a little more the past few years, but it's nothing new. For example, you had tools like Game Maker, and Pie 3D, back in the early 1990s which more or less followed the same principles. (I purchased copies of both packages. I also recall at least two others being existent or under development, though I don't recall their brand names.)
I don't think the game factories (i.e. all-in-one authoring tools) are really taking over game development or anything, though. Some people use them, many people still don't. The nice thing about them has always been that a game designer could build a prototype for an idea to pitch to more experienced devs... also, smaller teams can accomplish greater, more sophisticated feats of production value with roughly the same amount of work (or less) than doing things from scratch.
As with most anything, it's a pros-vs-cons scenario. Preference wins the day, yet again.