I don't actually hate any consoles or handhelds. I'm a firm believer that all consoles and platforms have their pros and cons, even if one of those categories is weighted a lot more than the other. With that said, here are some consoles I'm not a huge fan of for one reason or another, but again, I don't hate any of them.
Virtual Boy: The console has a pathetically small library of games and of those maybe 3 could actually be considered fun, but given how uncomfortable and cumbersome the console is to play, it's debatable whether those games re even worst it. If you've played the VB it's clear as day to you why it flopped spectacularly, however certain collectors lose their mind over it and pay ridiculous prices for it and its games. I understand a lot of this is fueled more by Nintendo collectorism and the platforms infamous quarkiness, but I've seen several people sincerely defend it as a misunderstood gaming platform. But yeah, it's a piece of shit no matter how you slice it.
Sega Gamegear: As a diehard Sega fan it's almost hard to admit this, but I've never been a fan of this handheld. I had a good friend as a kid who had one and even back then playing Sonic or other Genesis ports on it felt like a chore and something I had a hard time getting into. Later on as an adult I gave the platform another chance and I actually dislike it even more now. Part of this is I'm not a huge handheld fan, but also it just makes me want to play the proper Genesis versions of is games. And all the original releases for it aren't that great either, at least the ones I've played.
Every Atari console/handheld: I'm not ashamed to admit that anything released before the 4th gaming generation feels a bit before my time even though I was born in the late 80s. This even includes the beloved NES, however I actually like the NES unlike any Atari platform. While I admit I've never played any games on the Jaguar, 7800, or some of the old Atari computers like the XT, I've never played an Atari game I could stomach for more than 5 minutes. The incredibly crude, simple graphics and gameplay just don't so anything for me and in many cases I just find some of the old Atari games from the 70s and 80s to be unplayable now. There are several Atari arcade titles I find to be okay, but overall it's a company I have no love for or connection to. As for the Jaguar which is the only Atari platform I could even possibly consider wanting to play at this point, there are so few games on it that even look remotely appealing that I wouldn't lose sleep if I never actually did play the Jaguar.