For a small company, a limited TAM isn't a problem (and honestly is probably an advantage) if the overall market is big. Datacenters as a whole are a ~$30B market per year. The last thing you want as a small company is a bunch of different customers pulling you in different directions. By limiting your TAM, you limit the number of problems you need to solve for a few years, and if everything goes well and you start outgrowing your TAM, you can expand later.