We are told that Siddhartha was trying to understand the pain and suffering found in life. Evolution developed pain in order to provide reinforcement signals for learning (so you'll learn not to touch a hot stove again, for instance). So Buddhists are right that human existence requires pain. Learning systems are all imperfect so some pain will prove pointless (as will some pleasure).
Attachment may not be a bad thing. We should exhibit attachment (in moderation) to things that we find useful (clothes, shelter, food, etc.) Ignorance IS bad. Much of the 8 fold path is rational: we do want to have right effort, right action, right thought, etc.