Eh, not sure I'd say that; until I played it last year I'd heard a ton of negative stuff about Minish Cap, and man, that couldn't be further from the truth. Other than it having "only" 6 dungeons or whatever, it's a gem and it gets a lot of flak for no good reason whatsoever. If only Nintendo had gone in that direction for the DS games...
I feel like the Oracle games are overlooked mostly because when people think of GB Zelda, they think of Link's Awakening, but people recognize they're good games whenever they come up in conversation. Also they were released super late into the GBC life, no? They even had a couple of easter eggs when played on a GBA, IIRC. But yeah it's not like they're the targets of underserved hate like I've seen Minish Cap be plenty of times.