The hate is because they were the most visible "post grunge" Pearl Jam wannabe band, not that they were particularly awful among their peers. It's hard to exaggerate just how obnoxious alternative radio became in the late 90s when legitimately 75% of the plays were these manufactured poser bands. It's like clear channel took sadistic pleasure in making us listen to them skull fuck the corpse of Kurt Kobain for 22.8 hours of the day. That's basically what Nickelback was - not awful music, but rather the harbinger of the end times for independent radio and alternative rock.