I like Star Trek. I like the Orville. I like Stargate. They all have their own distinct feel, even within each show. I don't get a Star Trek vibe in Orville like I do Discovery, though that vibe is different than TNG, DS9, and VOY.
And, yes, this is completely arbitrary, since "feel" is highly subjective and it sounds like a "I know it when I see it thing." I don't watch Orville and go "Oh, they are doing Star Trek." I watch and go "That was entertaining." And that might be the difference as I have noted with many here. Discovery is not entertaining for them. Well, something can be Star Trek and not be entertaining. That doesn't change the "feel" of it for me to more Star Trek feel.
I really have no idea how to describe this, and it is starting to come across as condescending, which isn't what I want it to be. But, I truly don't get the "feels like Star Trek" argument with Discovery. Or, maybe my rejection of TNG is because it doesn't "feel" like Star Trek...I don't know any more