There is absolutely a glutted market in all of DC and Columbia Heights especially. I've rented out a one-bedroom apt as a vacation rental in my Columbia Heights home since 2007, long before Abb (on Craigslist.) Eventually I listed on VRBO/Homeaway and ABB. I used to easily rent 300+ nights a year at $125.00, or $140.00 peak season. Now I work hard to get maybe 200 nights at $125. ABB wants me to drop my price to $75.00 a night - um, no.
We have also suffered from all the recent shootings. Another host I know had two reservations cancel after the last one.
Chocolates on the pillow and fresh flowers are not going to make any difference. Luckily I have over 140 five-star reviews on VRBO, and reviews DO make a difference. Good photos make a difference. Comprehensive descriptions make a difference. But the fact is that most people visiting DC are doing the tourist thing and just looking for a bargain place to sleep that isn't too bad.
Until the market does sort itself out, as people eventually realize the income to hassle ratio might not be worth it, we just have to make do.