It would be a terrible decision to try and get a friend into, for example, Dragon Ball by getting them to watch Dragonball Evolution. Adaptations of anime are just bad movies; how can one get into anime by watching them? Many fans would agree that Dragonball Evolution is a bad representation of the anime, and would be a terrible introduction to the series, if not turn people off entirely.
A lot of what makes anime great doesn't translate into films. The facial comedy, the artistic animation, even some of the tropey mainstays of the genre, all fall flat in a live-action medium. Even if a viewer likes the live-action adaptation, it is not guaranteed that they will take well to the "unconventional" tropes of anime.