Because EXCUSE ME FOR A SEC:
Interviewer: If you could have played anyone else who would you have played?
Tom: Hermione and Hagrid. Other than that, I just can’t see myself play anyone else.
Interviewer: -laughing- Hermione? Why Hermione?
Tom: Well I just thought I’d be a brilliant Hermione. I mean, I thought Emma was great but I think I would’ve brought something deeper. No I’m just kidding.
Interviewer: But you would’ve had to kiss Ron Weasley at the end.
Tom: Well that’s the reason I would want to! Rupert’s a dashing lad and I’ve been trying to get on him for years but no go.
Source I LOVE IT. I LOVE IT.