Common issue with merchant acceptance - it's not enough to simply set up a merchant. They have to remain committed to maintenance and employee training.
This is why Roger Ver style guerilla merchant marketing fails in the long run.
Discussion
A full time marketeer needs to go door to door and explain how they can legally accept LN. Most of the merchants don’t understand that you need to register your transactions with a swap of cash. But then again you need supply and demand. Set up local groups of customers who are pushing merchants to accept LN. This is a fill time job, and who would cover those costs to make this happens.
Investing in software is one thing, but you need to push the use of it.