Seems like you hit a bad raid and I think you shouldn't base all of your desicion on one bad raid alone. Try to figure out what went wrong first - was it several people from your guild who had a bad day but they usually perform then next time it will probably be better. If the problems was the raid members you PUG-ed then don't invite them next time. If the next raid shows more of the same it might be the loss of the maintank but still you have to overcome that in due time.
Also while recruting and inviting randoms try to make notes of those you see preform and try to catch those for your next raid days aswell, seeing as they are saved with your ID anyways and hopefully they enjoy their stay in your raid. A good relationship with the same people will at least see you have options when raid invites go out and makes a more stable group = less chance of wipes.
"We have two ears and one mouth for a reason." - Buddhist belief.