[prodigal_erik]

It's a kind of tragedy of the commons. If two languages are basically equivalent yet incompatible, neither of the authors did something wrong, but it's a shame about the missed opportunities and problems that didn't need to happen.

[michaelmrose]

What missed opportunity? There is little reason to suppose someone that got motivated to create language A would have spent their time on language B if only they hadn't got involved in creating A. They could have spent that time learning to play chess or fishing.