The occasion that comes to mind for me was watching a bar band cover Blondie's "One Way or Another." The whole hook of that song is the little chromatic runs between B and D on the verses, nothing fancy. The guy didn't bother to play them, just played B, then D, then B again, etc. The whole thing just sounded dead and lifeless, and this was a guy with lots of experience in gigging bands. That, to me, is being a hack.
I agree, this was the first thing that came to my mind. There are so many songs that depend upon certain bass lines, even simple ones, without which they just don't sound right. To me a hack is someone who doesn't care about that stuff.
Anybody who can't play with a pick.
I would've said the exact opposite. I'm not necessarily anti-pick, but they sure as hell ain't necessary to be a good bass player, or to avoid being a hack.

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