I'm loving the new quests. Not only am I getting more gold per day on average, they're also much more fun to complete. Doing the "Play 75 murlocs" quest was the most fun I've had in Hearthstone for a while and I ended up getting three non-abusive friend requests over the course of completing it.
The presence of these quests also makes playing in casual mode more fun, since instead of constantly running into people practicing the latest meta deck, you often find yourself playing against weird decks put together to satisfy one of the new quests - it makes for some fun and competitive games.
Lastly, it's encouraged me to play my F2P NA account far more, since I can complete these quests even with a relatively small collection and don't have to worry about whether I can win or not.
I know the above is not entirely on the topic of whether or not the new quests have reduced gold generation, but I wanted to voice my support for the change :)