A lot of classes expect Reactions to work as per the PnP 5ed Base Rules (like the Paladin and Bard, among others). Not having Reactions working, even in a rudimentary state, will reflect poorly upon these classes. It also takes away from the game itself, being presented as a 5ed D&D game but yet don't follow one of the major systems.
I think I am speaking for many people here, and not just for myself, that most individuals want Reactions working in some way that has some control and is acceptable in some way. Even if we don't get 100% control, like Solasta with prompts, but something that at least uses the Reactions when they make sense.
I advocate for a middle ground in that Reactions are can either be turned on/off at any time (even during pausing), allowing the player to pause the game to turn on/off any Reaction, at any time and for any PC/NPC they control.
