it's fair to some extent. if you step to a chick you don't necessarily know what type of mood they're into. As the man and as the one who stepped to her, it's fair that you should lead the interaction and control it to some extent. The problem is like you said, when they expect you to entertain them. Some of them have this sense of entitlement like you're there for them and aren't trying to make any effort to connect with you. It's our fault though cause we gas their heads up so they expect all of us to be like that. it's nothing wrong with that though. maybe she just needs another type of guy. If you're talking to a girl, don't chase her conversation too much, if you're not feeling eachother, just gracefully eject.. (notice i didn't say "if she's not feeling you")
it's possible to control the vibe but not necessarily easy. I persoally believe that we all have soul or a certain type of energy (whatever you want to call it). Because of that, we can all connect as human beings with enough time and effort. the thing is, in 5 minutes you won't necessarily be able to. Usually you won't have that problem if you approach girls who already flirted with you heavy (she wants to be chosen). but if you find you can't control the vibe for some reason, one trick is to establish dominance first. strong eye contact, let her turn her look away first, there's more to it but you can't necessarily control it consciously. it's all about your mindset. but once you feel like she's letting you lead the interraction, then you take it whereever you want (lighter? flirtier? Wittier? sexier? where ever you take her she'll follow and she'll try to match your energy and style.
but you don't overthink all of this. if you have to force a lot of it, it's generally a bad sign. don't waste your time staying with a chick who's dull or being a bytch. maybe it's not her fault(bad day?) but either way, why try to break a challenge when you could be connecting with women who are more naturally your wavelength? if you're not feeling a chick or you feel like she's not feeling you that much and not even making an effort to try to connect with you, gracefully leave the convo.