Yes, I believe there is something called "quality" in filmmaking (or any other endeavor, actually) which is quite apart from one's opinion of it. I am not of the "relativist" mindset that thinks everything is a matter of opinion only. Those people are the Christians who deny global warming and evolution and think that at any moment a miracle could change physical reality.
Nope, good movies exist. Bad movies exist.
There are lots of really low budget movies that are fabulous -- "Return of the Secaucus 7" or "The Business of Fancy Dancing" or "Spring Forward" to name just three -- and there are lots of big budget blockbusters that suck ass ("Reds," "Ishtar" or "Prometheus" among hundreds of candidates). And not every disaster can be laid at the doorstep of studio executives.
"Showgirls" is a perfect example. Verhoeven has previously done "Turkish Delight," "Soldier of Orange," "Spetters," "The Fourth Man," "Flesh and Blood," "RoboCop," "Total Recall" and "Basic Instinct." He was not a novice without previous success. He should have known what he was doing, and how to make a good/commercially successful film.
And he can't blame the material. Joe Eszterhas wrote the script and Verhoeven had an ample budget of $45 million.
It's just that, at every point where a decision had to be made, every person on the production made the absolute WORST decision they could. The cumulative effect of this train wreck of -- not incompetence, what would you call it? Intransigence? -- is a movie that is just stupifyingly bad.
"Gravity", to bring this back to the thread, may not have been a thrill-a-minute after the opening 10 minutes, but it was at least competent. In fact it was flawlessly brought to screen. It was believably staged and nicely shot and well-acted. Howard called it "The Perils of Pauline" but that plotline is common in cinema ("Alien," "Panic Room," etc.) It's not an unsuccessful formula.
If he chose not to like it, he still cannot call it a "bad film." It just wasn't to his liking (which I believe he said).
In fact, I think it was a very good film - and I liked it.
Of course the ending was predetermined -- most films are. "Titanic" anyone? Bueller? Bueller? (I thought THAT was a very good film too.)