Maybe your problem is your market. Established development firms use JIRA or something else. They may be hooked on some of the big features that are part of the tool's complexity.
There are still businesses out there that have never heard of things like agile, or source control, and who manage projects by sending emails back and forth. Identify them and go after them. This may be all the tool they need.
My not totally practical advice? Get a job at a temp agency. You'll find your customers.
I'm speaking from experience. I have temped a few times in between jobs. Stapling and filing papers and all that. For small and medium sized companies that we tech people just don't think about - chinese graphite importers, freight forwarders, etc.
After a few days I'd start noticing things that I couldn't believe they were doing or using. "Why do they do it like that? Haven't they ever heard of process X, tool Y, technology Z?" Once in awhile I would even suggest something and help them out. It even landed me a bit of contract work on the side once.
I think there's a world of customers we're just blind to that aren't prejudiced to the existing tools, who might be persuaded into trying your software.