I would need a clear definition of "movie" to answer more precisely. Here is
the IMDB page for 10 hours of paint drying. It has a rating of 9.3.
It was submitted knowing the BBFC, the UK version of Americas MPAA, had to watch all 600 minutes to give it a grade. As a piece of protest art using visual medium, I applaud it but as a piece of entertainment to be enjoyed more intimately like at a cinema or at home, I would call it objectively bad. On the other hand I have probably enjoyed a good ~90 minutes of live stream from the ISS just watching the Earth spin by. Neither I would call "A movie" though.
"Bad" is also too vague a metric for me to really work with. I do think it would be acceptable to say that individual aspects can be done poorly. Take early photography. If a photo I paid for came out blurry or obscured, I would think it fair to call the outcome a "bad picture".
Going with those two examples, I would say, yes. A movie can be objectively bad.