If you consult https://chpl.healthit.gov/#/listing/10938 you will see that it is a certification of a subset of the full criteria (toggle 'see all certification criteria'). OpenEMR foundation says they had to raise $125k to do the partial certification, that sounds right. That is a good thing but some items like eprescribing are not certified, which is an absolute deal breaker to most providers. I would guess it's because you have to license a drug database. At ClearHealth we built and maintained our own drug db as open source also, it was a large endeavour. We had to lobby federally for there to be a carve out in the HITech legislation to even allow for an open source drug database to exist rather than the original requirement of two dominant existing providers codified in law. You can stitch together some other third party offerings to meet those needs but hardly anyone wants to do that.