"To try to force Twitter to be Facebook is a fundamental misunderstanding of how social networks might actually work," he said in an interview on CNBC's "Squawk Alley." "It might be that Twitter is the right size and it's growing at a nice pace."
Calacanis said outgoing CEO Dick Costolo built a great advertising platform at Twitter and was "exceptional at M&A."
"Wall Street ran him out of town. It was a huge mistake on their part and it's part of the reason that technology companies don't want to be public," he said.
Calacanis wants to see the company continue to acquire more start-ups, while using its advertising network "as common infrastructure against a collection of brands and apps."
"Not everything grows as fast as Facebook. It's unrealistic to think that everybody will be as good as the best player," he said.