I'm disappointed about some of the changes Fdev has been making lately in the name of simplicity, but I actually think that this particular move is a positive step in the right direction. It could be embellished upon with a more sophisticated system of looking for the minerals then just hitting the planet with the discovery scanner and getting a list, but let's face it, to most people other than Rock Rats landing on planets and looking for specific materials is an infuriating chore almost to the point of uselessness, and therefore Synthesis is equally useless to most due to the uncertain nature of material acquisition.
The proposed changes are going to change that completely and make material gathering and Synthesis useful for everybody who has Horizons. I'm actually pretty excited about it.
The Rock Rats are probably the sharpest, most dedicated players in the game, and I REALLY appreciate all the work they've done, even if I haven't really used the service myself. It's a shame they feel diminished by the upcoming addition.