No it's not. Being creepy and not building up a proper rapport is going to be harassment. Trying to use your status as leverage is harassment. Unsolicited comments or blowing up on someone after a rejection are harassment.
The exact same behavior, from two different people, will be considered creepy from an undesirable person but non-creepy from a desirable person.
Also, it's a given that an advance from an attractive person, in isolation, might not be creepy, but one from a less attractive person would be. The issue is the ugly person has failed to accurately evaluate their own personal dating market worth, which is a negative social signal.
It is clear (both through data and through basic anecdotal observation) that dating at work became dangerous to your career, specially if you are a men. So even the cases were it was done in a polite and non creepy way, are rapidly disappearing.