Sure, but there's 1) a performance hit because things that can be done at compile-time currently, have to be done at runtime, and 2) syntactically verbose/cumbe

Sure, but there's 1) a performance hit because things that can be done at compile-time currently, have to be done at runtime, and 2) syntactically verbose/cumbersome. They've decided that these things are not worth it to most people. Besides, it still is C++: you can totally compile everything without the moc (although its probably not very useful to do so), since the extra keywords are just #defines. I've personally never had any issues with the moc (but I did only ever use QtCreator/qmake, so...)