Scott McTominay had the visitors ahead before Hakan Calhanoglu struck Inter's equaliser just before halftime.
Sommer later said: "We're taking this point because it's a good point even if we would have liked to win because we had so many chances to score.
"I think we played a great second half, apart from the penalty we had at least three, four chances. In the second half of the game Napoli never had a shot on goal apart from that chance at the end.
"In the last week we have spent a lot and also earned important points. We knew that tonight it would be difficult, Napoli is a good team and we knew they would defend well. In the first half we had some problems, but we played a more than good second half.
"Now we will have time to rest because some players will leave for the national teams and when they return we will all fight together again to get more points."
He added, "Yes, of course. On the goal maybe we didn't defend ourselves very well, but it's not easy. The match with Arsenal had taken away our energy, it's a long season, with many matches, all to be played at a high level, we play every three days...
"We had Venezia, then Arsenal, all games that were not easy to play. But it's something we like, we have a lot of energy within the group and we will continue like this."