Normal, everyday flirting and fun interactions take place on a regular basis nowadays, they're just on a more equal footing which for the weaker sex--some men--means they aren't as fun. Men have gotten a leg up on the competition in the workplace by using harassment and abuse knowing that women would simply quit. This form of welfare for (white) men was standard and many a mediocrity relied on it and didn't have to work as hard as a result.  
Women and men both know how to use their sexuality to get ahead but now the rules are more defined and don't amount to the overly generous welfare hand-outs they used to be for men. But this was the more mundane side of sexism in the workplace. 
Weinstein engaged in unlawful actions--sexual assault, sexual harassment, threatening behavior. This has always been wrong and every man that engaged in it knew it was wrong regardless of the "era." Weinstein's lucky he didn't assault the wrong woman. Some women play for keeps.