Ever seen some things that are always the same? Every damn time? Across every timeline ever? These are Bland Tropes. They are boring, and they're recurrent and predictable enough to discuss in detail.
Key features of Bland TropesEdit
First and foremost, Bland Tropes are horribly convergent. Rather than exploring the consequences of alternate history, they kill hordes of butterflies.
Bland Tropes are lazy. The easiest reason for them to exist is to ignore what's actually going on in some part of the world by using an industrial standard Bland Trope instead. (This is actually a good benchmark of whether a Bland Trope is, in fact, being used. If an ATL looks at why things are so convergent, and observes the points where they aren't - even if those points have no overall effect on the plot - then it's just a matter of the ATL being convergent. And convergence isn't a bad thing if it makes sense.)