Exactly my point, the way the HPS is value is calculated favors Disc and can be very misleading.Holy EoL and Renew ticks deflate the value for Holy by extending activity time. I've seen reports where Disc priests have had several thousand more HPS than other healers and have less overall healing as such. Better to take total effective healing and dividing it by the total time of the fight if you want some sort of HPS marker for comparing healers from different logs, and looking at strictly just the effective total healing when comparing two healers from the same log. It's also why Disc can cheese certain HPS spikes, which they can not maintain.
This isn't a radically new and exciting concept, it's how DPS reports have been analyzed since TBC. Classic example was Supremus in BT. A good shadow priest could top Damage Done that fight but their reported DPS value was usually one of the lowest in the raid.
Of course, analyzing healing is much less one dimensional. A single well timed heal or proper dispelling are critical components to the fight that just never get really logged.