If your core customer base pulls in 4 or 5 figures a month from their own hustle, they might be willing to pay up to $15/month for features tailor-made for their needs.
Not saying there aren't people who truly like it. There are. But not everyone who uses it does.
Your comment might apply to addictive games, but you are being extremely dismissive towards a creative app that isn’t designed to be a slot machine. Who are you to tell others how to spend their time or money?
It's really that simple...
For me, .15 a day is negligible. I can easily imagine someone who creates memes for social media choosing to pay that, especially if they feel there is value in supporting the creator. Memes aren't frivolity any more than other content - they're one of the most popular forms of communication on the internet.