The 4GL thing didn't really work out, and is no longer a topic.
Can you be more specific?I don't think that this is true.There are millions of programs and robust applications made by using ABF/4GL code during the 90's and are still being developed/maintained.
Furthermore the language that Openroad uses is 4GL with object oriented extensions.You can literally copy and paste 'old' procedural ABF code that works in Unix into Openroad and with minor changes in declarations here and there you can have a fully blown GUI application,thus to use Openroad you have to know 4GL.So I don't see where it did not work out.