You shouldn't have to explain whether you "chose not to go" or just didn't get a date -- it's none of anyone's business. (And yes, that also goes for your mom.) There's zero shame in saying "no" even if nobody asked you to go, especially when there are waaaaay better ways to spend your night than going to a stressful school dance...
Check out a live show
If dancing to music is what you're missing, go directly to the source. Research all-ages venues within your area, and be open to checking out new genres. You won't even remember that dance in a few years, but you'll always remember discovering your favorite underground artist.
Comedy and live theater are also options, depending on where you live and what you're into. Even if all your friends are at homecoming, there's no such thing as going stag to a show -- and you might even meet new friends with a similar definition of fun.
Going to a dance takes a lot of energy -- and when you don't even want to go in the first place, it can feel like all of your energy. Instead, be creative. Make anything from a silly Vine or doodle, to an idea for a future business or cause. Many impressive adults spent their teenage years developing their ideas and growing into future innovators, activists and creatives who got far more out of life than a corsage.
Eat somewhere usually crowded with cool kids
Every high school has a designated hangout spot. (For mine, it was Wendy's, but the cool kids called it "Trendy's.") Hanging out there can also be a stressful reminder of your social status, depending on whether an open seat is offered -- and looking back, it's incredibly stupid.
A school dance moves the status-obsessed crowd to a different venue for the night, so you can have Trendy's (or wherever) all to yourself...and realize it's just a place to grab a bite, not the actual epicenter of cool. The experience will give you perspective for when the popular kids take it back over. Plus, you won't have to wait as long for your Frosty while realizing this.
Splurge a little
If you're working a part-time job to save for college, school dances can feel like a major waste of resources. That doesn't necessarily mean you should have no short-term savings goals. Those kicks you've been eyeing might be cheaper than tickets, dinner and fancy clothes for that homecoming date -- just don't go overboard by dipping into your long-term savings for a pair in every available style.
Go on a road trip
If you're old enough and your parents are cool with it, use your freed-up weekend for a "college visit." This kind of adventure will give you a sense of independence and remind you that there's life beyond high school. (Spoiler alert: it's even more awesome than grinding in front of your chaperoning gym teacher.)
Prank your peers
There's never a better time to prank people than when they're distracted by taking a dance (and themselves) way too seriously. Just make sure the prank isn't malicious or illegal...but sneaking in early to Saran Wrap a few toilets never hurt anyone.
Spend time with your family
OK, OK, your family may seem like a lame and nauseating alternative, but they are likely pretty awesome when you're not acting too cool to give them a chance. And trust me, when you leave for college and get homesick after a couple weeks, you'll wish you could spend a night just chilling with your parents or your most amusing cousins. You'll never, not once, wish you were back at that stupid dateless dance.