I think you're spot on with a solid plan to increase adoption but there are some problems with the economics and risk. Allow me to explain.
As you point out, it would require a huge effort to reach out to merchants and consumers. That's a lot of money up front.
At the same time, they're not getting much in the way of revenue, because the big selling point to merchants is that it's lower fees than credit cards.
So unless it works and works on a grand scale, it would be a terrible investment.
Beyond that, there are three more large problems that would need to be addressed in order to convince merchants to buy into this system:
1. Accounting complexity (tracking basis for capital gains)
2. Volitility (because their costs are going to be in fiat, so a conversion is generally going to be necessary)
3. KYC requirements (add a large amount of friction and make it difficult to deliver the easy-to-use experience)
Finally, there's also another major challenge with regards to the investors that would need to front the aforementioned money: market protections
IF the plan works and it works on a large scale, what's to stop someone else from competing without having to have paid for all that education of the market?
Once the market is established, others can start up with a fraction of the cost and create a compatible system. Lower costs mean they'd be able to charge lower fees and beat the first mover. In contrast, making a propritary payment system allows for vendor lock in, which makes the big up front investment more palatable.