It's not about being "Casual" or "hardcore", rather it's about being lazy or not. Bungie has created a raid recruitment thread where you can link up with guardians in under 10 minutes. Other third party websites are available and Reddit has a subthread /r/fireteam I believe. Don't blame bungie for not putting in matchmaking.(which I believe would be a terrible thing) Quit whining about the lack of matchmaking and go join a casual clan, search for hundreds of other guardians willing to raid in the many services provided, or you can just leave the game over something that insignificant.