You've been there every single time they needed you.
You've been their guiding beacon, in times of adversity, rejection, destitution!
You've been their source of inspiration ever, if not anything less.
You've understood their implicit expectations, and satiated those before they realized they wanted it.
And what happened after all that?
You were tagged nice.
You were friend-zoned.
You were expected to take care of yourself when in agony.
You were expected to get things done for yourself, without the slightest hope of any help from anyone.
And no matter how explicitly you implied your expectations to that someone, all you got was a cold, subtle denial.
You helped people and they clung on to you for more.
You were taken for GRANTED!
You respected people and you were taken for granted.
You tell me, why would being nice be a motivation for anyone?