Alderweireld headed home an 80th-minute corner as Spurs came from behind to earn local supremacy and move above their neighbours in the pursuit of European football.
"Of course [Bournemouth] hurt," Alderweireld told the London Evening Standard. "There was some negativity about us in the media - that's normal but nobody sees how hard we're working to change things.
"I don't want to say, 'No, all the criticism, everything [people say] is untrue' but of course it hurts because we work so hard. Everyone wants to change things, everyone wants better results.
"Sometimes you just need some momentum and confidence. I think from minute one [against Arsenal], after a couple of seconds, we had a shot on goal. That showed what our intentions were."
He added: "I think after the lockdown defensively we've been a lot stronger. We're getting there. We have some momentum going, so I think last night can be a changing point. In this period when things aren't 100 percent going your way, the thing is to work very hard and it'll come. Last night we showed we have character. At difficult moments we were there. And then we have quality [to score]."