That was a lot of bullcrap responses from Matt and Brad was way to chicken to actually question those responses.
Matt basically want the work the plugin authors put into the plugins to remain free of charge so he can stuff their code into the core more easily? So again the only commercial plugins he really support are those that have a similar structure as Akismet. That is: wrapper plugins.
So he dislikes Shopp, Gravity Forms etc and considers them to be against the nature of WP even though they are GPL because they charge money for their work and support etc.
I think plugins like Shopp, Gravity Forms is way more important to the future growth of WordPress than yet another "original" blocky wordpress theme for $39-$70.

Making a complex plugin takes more time than making an "advanced" theme but since they cant put themes in core they have no problem promoting commercial themes.