Alex Revell gave the Millers the lead after 31 minutes of Saturday's League Two clash at Don Valley, but the home side missed a host of chances and Akinfenwa made them pay.
"What a way to finish the season, with a last minute equaliser," Boothroyd said. "That's why we managed to stay up because we keep going.
"All credit to Rotherham because we both put on a performance and both tried to win the game and in the end I thought it was a fair result."
Boothroyd said he would be talking to his players this coming week to "decide where we go from here."
He added: "I asked them to finish it off right and that's what they did and I'm hoping now to have a chat before the end of May because I want to make sure we get a good squad together for next season. There will inevitably be comings and goings, but I want to get a solid core ready for the start of next season."