The Reds slumped to their fifth defeat in six games after fading in the second half of their 34-15 loss to the New Zealand side at their home Lang Park on Saturday.
"I couldn't be more disappointed with the performance of the bench," Stiles told local media.
"It takes 23 guys in modern day rugby to win football games, it's not just about your starting XV, it's about 23.
"Going into this game with a couple of the minor changes that we made, I thought our bench would be a really good contributor for us.
"But I was just really disappointed with their performance when they came on — and I told them that in the changing rooms."
The Reds entered the season with high expectations after recruiting a number of seasoned Wallabies but the Brisbane side have been a huge disappointment, with established players out of form and on-field discipline lapsing badly at times.
Stiles, a co-coach last year with the now departed Michael O'Connor, is already under pressure in his first season solely in charge and vented his impatience with players like scrumhalf Nick Frisby, who was demoted to the bench against the Hurricanes after struggling in the starting side.
"(Hooker) Andrew Ready knocked on, Nick Frisby played poorly," he said.
"Those guys come on fresh, they've got to come on and contribute and it wasn't good enough."
After conceding a 14-0 lead early, the Reds battled hard to keep in touch at half-time but were over-run too easily in the finish.
Worryingly, stand in captain Stephen Moore suggested his team was not fit enough to stay competitive with the benchmark New Zealand teams.
"They're a good team for a reason, because they play that 80 minutes," Moore said of the Hurricanes.
"We made some mentally tired decisions in the final minutes when the Kiwi sides are so good at playing the full 80.
"That's why they're so good isn't it -- they play the full 80 minutes and that's a big learning for us.
"Stilesy spoke about the guys that come on the field, need to have a big impact on the game, particularly after the two weeks that we've had away."
(Reporting by Ian Ransom; Editing by Greg Stutchbury)
