I don't think I've seen a single post yet trying to argue for why it is good outside of the op, so I won't bust my ass to make a proper counterargument.
Game is lower tier Zelda, probably the worst sprite-based game after Zelda II.
Real impressions below c/p from an older thread:
In my quest to 100% all zelda games before Skyward Sword releases, I recently picked up minish cap for a replay. I thought this would be a good place to start, as I didn't remember much more of it than generally not enjoying it too much, and it seems to garner such high praise here I thought I might have been missing something.
New features
Minish cap is an interesting mash up of 2d Zelda and Wind Waker gameplay elements, but it feels just like that to me - a weird mash up. Minish cap has the slowest walking speed of any zelda game ever, EVAR. You walk excruciatingly slowly, necessitating you jamming R at all times. Not a pleasant experience on any backlit iteration of the gba. Whereas text up to this point in 2d zeldas was always minimal, unintrusive, and snappy, the text here adopts the 3d paradigm of being way too slow, pointless, and repetitive.
The context sensitive r button is nice (aside from the irritation of constantly rolling). You can pick stuff up without switching to a bracelet, theres a dedicated 'talk' button, you can shrink without switching to an item, etc.
The Minish Cap
Speaking of shrinking, let's talk about the namesake gimmick. It starts out decently, you get shrunk down to a microscopic level and realize the implications of the amount of content they could pack into a zelda world with this mechanic. Unfortunately, it just never really pans out. There are a couple instances (such as the fountain quest in the village) where the shrinking mechanic feels like its actually expanding the amount of usable space, but otherwise it's purely cosmetic, "you can't go through this tiny door, you have to shrink first!". It really adds almost nothing to the game, and I think it qualifies as a gimmick in the worst sense.
The Dungeons
Most of the dungeons are serviceable, but some, such as the sky dungeon, are almost an entirely straight line. This would be kind of OK if there were more of a focus on combat, but minish cap is perhaps the easiest 2d zelda ever. I honestly don't think I died once. So running straight through a dungeon in a straight line just feels like shitty design. I beat the game less than a week ago and can already barely remember the dungeons. There also aren't very many.
The Items
The items are a mixed bag in this game, ranging from awesome to garbage IMO. For example, the mole mitts are a really cool new take on the shovel, though I feel like they were never really utilized to the concepts potential (aka just a palette swap for the shovel). The roc's cape is also an incredibly cool update to the roc's feather, allowing you not only to jump but to glide.
The four sword upgrades were kind of cool, I liked having multiple sword upgrades. It's always satisfying to one-hit a monster that would have given you some trouble earlier in the game.
I've always had a soft spot for the boomerang in zelda games, but in MC it's borderline worthless. You only take it out to kill one or two enemies ever. There's an upgrade though, so that's cool.
The gust jar is an extremely poor replacement for the hookshot. Seriously, this may be my least favorite zelda item ever. You have to hold it down for a couple seconds before it even does anything, which is irritating, and its use is extremely limited.
The cane of pacci is kind of lame in concept (it flips things over! hurr), but actually useful throughout the game.
The mirror shield makes a comeback! One of my favorite zelda items, but you don't actually get it until AFTER you beat the game, so it's worthless.
Sidequests/additional content
This is where the game really shines. There is a ton of optional content, not least of which being kinstones, which I thought was a really great system and I'm surprised we haven't seen anything like it since. Tracking down every fusion is kind of a pain, but its a really good way to keep things interesting and pack a ton into every inch of the map.
There seemed to be lots of hidden dungeons as well, mainly from kinstone fusions. Tiger scrolls were a cool addition though the moves were mostly useless, and using shells for figures was kind of cool but ultimately a huge headache to collect all of them as you had to sit through so much text every time.
Audio
The audio is fine, but almost everything is recycled zelda songs - not even reorchestrated. Lame.
Conclusion
Minish Cap is definitely worth playing, but it clearly sets the series on the course that leads to the underwhelming Phantom Hourglass. The map is tiny, the gimmick is gimmicky, there are few dungeons, and the new items are mainly crap. Getting all the content ups the enjoyability quite a bit, but the lack of difficulty and linear nature make it a fairly forgettable experience. Although much of it seems haphazardly cut/pasted from Wind Waker, the pixel work is stunning, and it is definitely one of the best looking 2d games ever, IMO.
TLDR:
+beautiful
+kinstones (I actually liked them)
-Link is reallllllllllly slow
-not a single above average dungeon
-shrinking is a poor gimmick
-slow, constant text
-crappy music
-poor item selection
-no memorable characters
-few memorable boss fights
All the above negatives considered, that's basically a laundry list of everything that could go wrong with a Zelda game.
I have a really hard time seeing how anyone even puts this in their top half of Zelda games, let alone favorite (assuming they're a fan of the series).