Because I can make the same or more power with a SFT and not have to deal with the hydraulic lifter issues.
At one time there was some class that required hydraulic roller cams. The HR is so RPM limited we did everything we could to get them to RPM half assed reliably to 7200.
The we started looking at comparable builds with SFT cams and the HR was always no better than the SFT and sometimes it made less power.
When you get to the point that a SFT won’t make the power you want you just need to use a solid roller.
I have done a lot of HR lobes with solid lifters on them. Set the lash to .002 cold and send it.
At this point the money for the HR just doesn’t make sense in my world. And in the end you still have a shock absorber in the system and all the havoc that brings to the valve train.