They appropriated the LGBT experience to gain viewers, and then threw it all away after they didn't need it anymore.
Robin barely even seemed to tolerate Vickie in the finale, and then she was gone. No Enzo's date. That's only for straight couples.
What purpose did any of it serve? I guess they made the straight characters look better for accepting Robin and Will. Steve benefited from it. Mike got his absolution from Will in the tower scene. But none of it mattered for the actual queer characters.
The best we have to look forward to is acceptance, I guess. Love only exists for straight characters, and "crushes" and high school love only last if you're straight, too.
But, hey, they can go cruising at gay bars now!