The presenter, who fronted spinoff Strictly Come Dancing: On Three in 2004, told the BBC that Forsyth is "too old" to continue on the reality talent dance programme.
Collins said: "I still think Bruce in his day was the best at what he did, but I think he should have given up three or four years ago.
"As legendary as he is - I grew up loving him, as did my parents, as did my grandparents - he wasn't particularly nice to me on that show."
He added: "I loved him and they do say never meet your idols because you're always going to be disappointed and in the case of Bruce I was disappointed. He was very rude.
"But he does a very, very difficult show on TV, and I think particularly on that first series, he may have found it difficult.
"I still love to watch it, religiously. I never miss it, if I'm away it's recorded. It doesn't get much bigger or better than Strictly."