The Incredibles director Brad Bird and Knocked Up's Judd Apatow were among those who tweeted their concerns.
Bird, whose films also include Mission: Impossible - Ghost Protocol, said it was "another cut to the already bleeding-out cinema experience".
Apatow, also creator of the Netflix series Love, said the function was "ridiculous and insulting".
The feature allows users to play content from half the normal speed up to one-and-a-half times faster, and is reportedly only available to Android mobile users.
Netflix vice-president Keela Robinson said in a statement: "We regularly test new features that could help improve Netflix.
"This last test has generated a fair amount of feedback - both for and against. This is a mobile only test and gives people the ability to vary the speed at which they watch on phones or tablets...
"It's a feature that has long been available on DVD players - and has been frequently requested by our members. For example, people looking to rewatch their favourite scene or wanting to go slower because it's a foreign language title."
The function could also appeal to viewers with a backlog of box sets to binge on. In fact, some people have for a while been indulging in "speed-watching".
There's even an "efficiency expert" out there who advises watching at faster speeds to make the most of your viewing time.
"More jokes, more laughs, more drama, more suspense - same time," Michael Kirk, creator of the Efficiency is Everything website, writes. "Efficiency: Like an assembly line, if we increase the speed of the line, we will see more completed.
"Same jokes, same plot, and at 10% faster - you won't notice a difference."