Gabriel Martinelli had the Gunners ahead after halftime, but Pedro Neto found an equaliser after jumping from the bench.
Later Arteta told Sky Sports: "I think we dominated them, we were the better team in many phases and situations in the game and after going ahead, very disappointed in the way we conceded. It was so poor. It is not our standards and we don't accept.
"Really proud, but at the end we are here to get the three points and we didn't. It is a second phase set piece and we were disorganised. We don't reorganise quick enough and you can't allow the pass that way.
"You need the quality of Neto to do it but our standards were not good enough. They are all disappointed as a team. I'm very proud of the team with how they reacted. We wanted the three points and we didn't get them.
"You could see everything was flowing but again it is about winning. We have a clear vision how we can evolve the team. What we find out is that we have to change something big because we have problem after problem.
"My biggest fear is physically to get players at their best for 90 minutes. With that I'm fully confident we will have a good season."
He also snapped: "When it gets nasty, show your teeth and show how much you want it. When it's Disneyland it's very easy. Everybody's next to you, telling you how beautiful you are.
"When it gets dark and difficult and everybody's questioning it, that's when I want to see people. I'm looking around."