The Hornets captain fronted up after a 3-2 defeat to Arsenal on the final day of the season saw them finish inside the bottom three.
Watford finished 19th, a point away from Aston Villa, who secured safety in 17th with a draw at West Ham.
Sharing the full story, not just the headlines
And Deeney was brutally honest when assessing the ramifications of dropping down to the Championship.
“You have to look at the bigger picture. It’s not a today, last week, it’s a reflection of the whole year,” Deeney told Sky Sports.
“We’ve not quite been good enough. It’s shown again today, it’s frustrating, it’s disappointing. It’s heartbreaking for the people who work behind the scenes.
“A lot of people that work at clubs normally get affected by relegation. We feel sorry for them. I’ll take the stick in regards to what comes on social media.
“But the real harsh reality is people will lose their jobs because we’ve not been good enough.
“As players we have to stand forward, take that and as a club and a community we will have to go again.”