Andrew Tutte's seventh minute strike but Dale ahead only for Torquay to then score four without reply and then have Aaron Downes sent off. Jason Kennedy missed the resulting spot kick, before substitute Ray Putterill scored the visitors' second goal in the 85th minute after having an earlier effort cleared off the line by United left back Kevin Nicholson.
Coleman said: "I feel for the fans who pay their hard-earned money to come all this way. We don't go out deliberately to play badly. We were very, very poor and Torquay deservedly won by punishing us with some clinical finishing.
"We haven't set out to play like that, we will learn from it and I think we will come back stronger. We showed at the end that we didn't throw the towel in, we kept going, we could have easily got something out of the game.
"On another day we would have got something out of the game, which sounds bizarre because they could have put the game to bed by a much larger margin. We have got to be tighter defensively, we have got a back four where two of them have only played three League games each. But this is all part of the learning process and they will learn from this.
"At the end of the day, we didn't play well enough, didn't pass the ball well enough because we have got a system of play but people who write us off quickly do so at their own peril."