I often go alone and don't have a problem with it. For me, the biggest reason is seating. You can almost always find much better seats if you're looking for singles. You can almost always get a single seat in the front half of the orchestra if you have some flexibility with your schedule. Also, if you don't have to coordinate schedules, you can monitor the tickets and just grab an open ticket and go.
I don't have the boredom problem either. I'm the type of person who reads the Playbill cover to cover, and I also like to explore the theatre a bit. I usually get to the theatre just before the show starts, and at intermission, between reading the Playbill, checking out the theatre, and reading the reviews and looking at the pictures posted outside, the time flies by.
"What was the name of that cheese that I like?"
"you can't run away forever...but there's nothing wrong with getting a good head start"
"well I hope and I pray, that maybe someday, you'll walk in the room with my heart"