Well because a R/S is simply a change in the NUMBER of shares you own, with parrallel change in value.
In a Reverse Merger your shares acutal VALUE is changing to reflect the addtional Capital or Assets that have been absorbed by the company.
Therefore as your acutal share count may be reduced or increased...it is not a "split" in any way. You end up with "new shares" reflecting recently Merged Assets and a New entity.