It's up to the authors to decide which license they will choose. Complaining that you can't use a GPL3 DWG library in your code is no different than complaining

It's up to the authors to decide which license they will choose. Complaining that you can't use a GPL3 DWG library in your code is no different than complaining that you can't use Autocad's DWG library in your code: it's not yours; you do not get to decide the rules for using it.