Objective criteria is what differentiates the artistic masterpieces from mediocre works - not how you happen to think about them.
For example, Rembrand's work is FAR better than the work of some untalented nobody, despite the fact that someone would like Rembrand's paintings less.
'Contact' is FAR better than 'Lost in space' even if someone would like 'Lost in space' more.
So who is it that defines these objective criteria. Let's consider Rembrandt for example. During his lifetime and long after all of his later work such as Conspiracy of Claudius Civilis, was considered substandard and was despised. Only much later were they re-evaluated and are now considered masterpieces. Why is that? It's because the criteria used to judge them changed. It's because the criteria are subjective and represent the values and tastes of the society, people and time that are making the evaluation.
There just is no such thing as an objective criteria by which to judge the quality of something. Who's to say that 500 years from now some very smart art critics will "see" some qualities in "Lost in Space" that make them value it much more highly than "Contact"
You're opinion of Star Trek V is absolutely valid and you are entitled to it, but it is absolutely ridiculous to claim that your opinion is "objectively true" or in some other way more "true" than that of someone who likes the movie.