[mv1]

dotBen has it about right. It sounds like your startup operates in a specialized domain, so most investors won't have the expertise to understand it - which means they likely won't invest as you've discovered (and as hard as it is to believe, it turns out you don't want them to).

The startup I co-founded struggled with exactly this issue for the same reason - the company operates in a specialized domain. Just like you, customers got it but investors didn't. After about a year of fund raising (and working with customers) we found someone with the ability, desire, and domain knowledge to invest and we got a funding commit after a 1 hour first meeting. With the help of the lead/early followers, the round filled out shortly thereafter.

If you have something valuable as measured by customer interest and, ideally, adoption, hang in there and keep looking. Try to figure our quickly who will lead a round and who won't. Unfortunately, it is hard to tell the difference until you experience the process with someone who decides to lead.