IMO I find Joyce speech to be actually really constructive and she gives him words of wisdom which actually open his eyes even more. The interaction was really realistic and I actually really appreciated Joyce's actions for actually doing that circumstance, she probably was really scared about her daughters life structures and wanted more for her daughter so she took the encouragement to actually tell Angel to make the hard decisions if Buffy could not. Even Willow stated that she hoped for the best for the relationship. It wasn't just Joyce, the difference is that Joyce took action.  


“Good. Because when it comes to you, Angel, she's just like any other young woman in love. You're all she can see of tomorrow.  But I think we both know that there are some hard choices ahead.  If she can't make them, you're gonna have to. I know you care about her. I just hope you care enough.”


I thought the interaction was really realistic and it felt she actually cared. And we see her actually take notice and acted like a mother protecting her daughter. Because at the end of the day, Joyce was really right about the unique relationship of "Bangel"

In the long run, Buffy would have forgiven her mother words of wisdom.