Nothing, it is just that nobody bothered. There have been a bunch of classic-VB-like languages (even IBM made one with their 'Visual Age for Basic' - though they really missed the mark on the IDE side, but the language and features were very VB6-like), but pretty much all of them either get abandoned or miss the entire point of classic VB by focusing on one thing (usually the language) while ignoring another (usually the IDE or sometimes the fact that classic VB is almost a 'live' system and instead they put a clear C-like separation between editing and compilation)... or miss completely by doing all these things wrong. Assuming they do not die off before managing to make anything usable, of course.