Main reason why Vanilluxe gets seen in a negative light for being an object based pokemon isn't entirely because it's based on an object but it's because it doesn't feel like a natural existing organism in it's setting. In the sense that it doesn't look like something that would you'd imagine as a creature in a fictional setting filled with fantastical animal like creatures. Pokemon like voltorb, magnemite, and the litwick line work simply because they'd appear to fit within somewhere in a setting. A such as a powerplant and haunted house respectively. Litwick line even more so since they're ghost on top of being since they could appear potentially anywhere and wouldn't stick out too much especially if there are other ghost pokemon in the setting. Even in an ice based setting vanilluxe and it's evolutionary would stick out because compared Froslass (an ice spirit), glaceon (an artic fox), and alolan sandslash (an armadillo/pangolin adapted to the cold) but an ice cream cone is pushing when it comes to associating it with the setting and thus breaks immersion to the detriment of some people. At least that's my understanding of it.