The Royals led 2-0 at half-time thanks to two goals from Gylfi Sigurdsson but should have been even further ahead of a poor Bristol City side at that stage.
"The only criticism I have of my players today is that they didn't get that third goal," said McDermott.
"We created a lot of chances, but having said that the key is to win games and get three points.
"We didn't go into this game expecting to win. You can't expect anything in this league.
"It's so tight to the top and to the bottom. Our aim is to get into the top half and see where we go from there.
"The players are enjoying it at the moment. They are enjoying training and the staff after making sure they get looked after and are having their rest and preparing for games properly."
Reading's opening goal came after 12 minutes when full-back Ryan Bertrand made a run out of defence and fed the ball out to Jobi McAnuff, back in the team after completing his suspension.
McAnuff whipped in a cross from the right which Sigurdsson firmly headed past Bristol City keeper Dean Gerken from close range.
Sigurdsson scored Reading's second in the 21st minute.
He was pushed over by Paul Hartley and referee Paul Taylor pointed to the penalty spot. Sigurdsson took the kick himself and fired home his 12th goal of the season
Reading, and Sigurdsson in particular, could have stretched the lead even further.
He almost scored a third in he 38th minute but saw his shot headed off the line by Hartley.
Three minutes before the half-time whistle his close-range effort was blocked by Gerken.
Bristol City manager Gary Johnson said "Credit to Reading they are on form now and when the second one went in from the penalty that killed us.
"We sort of got a response from the team after the break when Reading weren't so potent, but we didn't do enough to win the game. We didn't do enough to be unlucky.
"I think if Reading keep that going there's every chance of putting enough points together to make a run for third place.
"We created one decent chance from Jamal and the keeper made a good save. That was it.
"We had to work hard to stop them being so dangerous in the second half but that took our energy away from attacking."