The real reason the hive/taken are angry? Crota ordered pizza from the traveler and it took longer than 20 minutes to deliver... Crota laughed and said "sorry traveler pizza is free as per your advertised guaranteed delivery time" The traveler was angry because he thought the hive boomers that delayed him were sent by crota so he wouldn't have to pay. The traveler entered a state of depression because his wife ended up leaving him because he couldn't pay his rent... So the travelers guardians killed crota and took the $20. Oryx then invaded the system to get back the 20 bucks that crota borrowed from him...