They were. My first employer partnered with eInk back in like 2012 to bring a line of ESLs to market. The reason you're not seeing more of it is because in the US the companies prefer to purchase a "turnkey solution" whereas in Europe companies are more apt to develop custom software to integrate the ESL with their systems. And the major ESL supplier in the US, Pricer, uses on-premises servers and IR to update labels which is an expensive proposition. So you're limited in how you can pilot the technology.
I actually think there's a lot of room at the low end of the market to sell an on-premises ARM- or NUC-based server which interfaces with the tags over a radio link and provides aggregate data back to a cloud-based system for control and pricing updates. That would get you the millions of convenience stores who have to pay 3rd-party contractors to do their shelf labels. This would be especially brilliant if you combined a software fee with equipment leases so that your solution is an operating expense instead of an upfront capital cost.
I actually think there's a lot of room at the low end of the market to sell an on-premises ARM- or NUC-based server which interfaces with the tags over a radio link and provides aggregate data back to a cloud-based system for control and pricing updates. That would get you the millions of convenience stores who have to pay 3rd-party contractors to do their shelf labels. This would be especially brilliant if you combined a software fee with equipment leases so that your solution is an operating expense instead of an upfront capital cost.