Why is objectifying people considered a bad thing?

[Alexander]

ok lets pretend 50% of people are fine to be called objects and 50% of people are unhappy to be called objects and would prefer to be seen as above objects 

which group do you think will receive better treatment (assuming looks etc. are same)?
if you're fine being called an object then expect to be treated like one i.e like trash.

this isn't an objective world. its full of trickery and deceits so that people can gain the upper hand