The Briton has laboured at the wheel of a below-par car all season but appeared utterly crestfallen today at the end of a race where the 2013 McLaren's shortcomings were laid bare.
After qualifying down in 14th place, Button - the victor in Montreal just two years ago - improved just two places at the end of 70 racing laps.
The 2009 world champion finished a lap down on race winner Sebastian Vettel and also had to play second-fiddle to team-mate Sergio Perez, who himself was a frustrated 11th at the chequered flag.
"I've never been so pleased to get out of a car," Button told BBC Sport.
"It wasn't the best race for us as a team. This place normally treats us well.
"We got lapped - easily lapped - and it was like we were in a different category.
"We did different strategies on both cars but we just didn't have the speed."
Asked whether it would have eased his anguish to have got his car into the lower reaches of the top 10, he said: "Whether it's one point or two points, that's not what we're here to achieve. We want bigger things than that.
"I think if we'd scored a point today we'd still be disappointed."
A poor showing in Montreal was the last thing Button would have wanted ahead of his home race at Silverstone at the end of the month, although he believes the high-speed Northamptonshire track should at least showcase the strengths of the MP4-28.
"Our car does work on a circuit that's a little bit faster and flowing, so I'm looking forward to Silverstone," he said.
"It can't be as bad as here."