Shows like this, and movies as well, often have trouble finding an audience. Lots of people want it to be easily categorized as a drama, or a comedy, or whatever. Sure, dramas usually have lighter moments to break things up, and comedies often have serious moments, but usually it's rather obvious the genre that they're going for.
The Orville is confounding a lot of people because it doesn't fall clearly into a given genre. Those who expected and wanted outright comedy are disappointed that it's not wall-to-wall laughs. I don't think anyone expected "heavy sci-fi" but the production values and overall look seem to imply a more serious show, and the lighter tone runs counter to that.
Someone at previously.tv said it's like they tried to redo The Next Generation, only with "real people", not 24th century boring perfect people with no flaws and no personality. Yes, that's exactly what this is. Helmsman has no trouble telling the rest of the bridge crew that the new XO is a total bitch. Tactical guy just wants to be able to drink soda on the bridge. The pilot episode made a point that there are 3000 ships in the fleet, and they have to staff them all. Somebody at the Academy finished 399th in their class, but still earned their commission. They're not going to be assigned to the flagship; they're going to some low-level exploratory vessel like The Orville.
And that's what I like about this show. Sci-fi to me is its own genre, transcending drama or comedy or whatever. The XO ordered a "cannabis edible" from the replicator, and the Security Officer ordered tequila while she was the acting Captain. No, you'd never see that on Star Trek, but it is something that real people might do. I like that, not because it's funny, or not funny, or realistic, or not, but because it's different from what we've seen before.