Good point, and that's why I included the word "resistive" the first time I mentioned splitters and their loss values.
Directional couplers are significantly more expensive and more limited in bandwidth, especially for tighter coupling values. And they will be physically larger if they have to cover lower frequencies.
Even though the OP mentioned a high quality 6dB splitter, it most likely is not directional if it was for cable or DTV with a cheap F connector. The poorly controlled reflection coefficients of those connectors would significantly degrade the directivity of a good directional coupler.