The problem with Sonic Lost World is that there a lot of ideas, but no focus. It tried to be both complex and simple, soft and edgy, nostalgic and new, but nothing gels and as a result it comes off as an unappealing cacophony of ideas that feels like it tries too hard to appeal to too many people at once. The weird part is that staff were confident that the game was going to be the game that received critical acclaim, despite the fact the game is a mess.
Also, SEGA (or more specifically the people involved with development) should receive criticism just like anything else. You think products improve because everyone pretends everything is okay and people just blindly accept everything? No, to improve you need to understand what your mistakes are and how to fix it. It's a natural human instinct that applies to everything, and video game development is no exception.