Because there are many other factors in choosing a hosting provider (price, performance, features, security, scalability, etc). It seems a bit weird that all of these would be less important to someone than IPv6. Though I guess I can imagine that for some businesses it could be hugely important. Was just wondering what OPs business was that it became an overriding priority.
Rolling out an IPv4 only stack right now is debt. IPv6 has finally hit the point where there's no longer an if portion to the question, but rather a when. Every server rolled out in an IPv4 only setup, every service built, etc, is one more potentially service-interrupting area that will have to be changed when port your stack to IPv6. If you're young and small, starting as IPv6 native means that the next few years you'll have an advantage over your competitors because they'll be thinking migrations while you're thinking about growing your business.
That's reasonable, but I think you significantly underestimate how long it will take before these sorts of conversions will become necessary. IPv6 is 20 years old. These things take decades not years.
In addition, I think you overestimate the difficulty of conversion. Most backend servers run on 10.x.x.x networks and that doesn't need to change. You just need a proxy in front of them that can speak IPv6. Installing a new proxy does not sound like a hard job. It sounds trivial.
