- An opinion is something that is a matter of personal belief, or judgement. If I say 4 cookies is too much to eat for dessert... there is no way to test what is "too much". It is my opinion that 3 cookies is the most that should be eaten. My daughter has a different judgement.
There are objective reasons why a certain amount of sugar is too much or not enough. There can be a lot of different hypotheses/theories about how to analyze the effects of sugar on the body/mind because there is so much complexity in the physiology/psychology of dietary choices, patterns, habits, desire/appetite, etc.
Where you get confused... is that you make a jump from carefully selected facts to an opinion, and then you think that because your facts are correct then you opinion is correct. It doesn't work this way, another person will base their different opinion on a different set of facts that are equally correct.
I don't assume I am necessarily right. I just think I am. You assume I am incontrovertibly convinced that what I think is right must be right and that I ignore reasoning that defies my current conclusions. That's not true, but in your world doubt is an opening for pushing your own views/values, which are biased toward pleasure, fun, and risk-taking and biased against risk-avoidance/minimization as you don't see the possibility of happiness in those.
You look at sex as something dangerous. Your facts are correct... people do get sexually transmitted diseases. And there are people who have obsessions based around sex. Your disdain for sex is based on a value judgement. That you have selected facts to back it up doesn't make it any less subjective.
Bodily contact is dangerous and usually unnecessary. It is not difficult to have a happy life devoid of bodily contact with other people and/or animals. Even so, some forms of bodily contact are more intense and risky than others. Sexual contact is one of the more intense and risky, and so many other choices for bodily contact would be better than sexual contact for people who cannot avoid bodily contact altogether.
I look at sex as something pleasurable. My facts are also correct... people form close bonds in sexual relationships. It is a fact that most people are sexually active and live happy productive lives with good jobs interesting hobbies and healthy families. My love for sex is based on a a value judgement. Lying naked, skin to skin, with a lover is something I find deeply enjoyable. That I have selected facts to support this pleasure doesn't make it any less subjective.
Sex is a drug. A pimp-prostitute network is a drug-dealing network. A prostitute is a victim because her/his body is inseparable from the drug being trafficked/sold. If other recreational drugs were derived from human bodies as well, it would be pose similar problems and be similarly disturbing.
The same is true for any value judgment. Is airplane travel justified? Is Country music horrible? Is God dead? These are all opinions... you can come up with facts, but it is the leap from fact to subjective judgment that brings us to our system of beliefs.
You can't justify airplane travel generally, but you can look at specific reasons/situations it might be justified, and then consider what it takes to maintain the economy needed to sustain an air traffic system suitable for accommodating the needs of justified air travel.
On the other hand, you could also consider how surface transit could be better and whether the time saved by flying is really worth the additional economic and environmental costs, not to mention the safety risks of flying.
Country music, like all forms of music, can be evaluated for its quality by those who appreciate it; and a certain aspect may be more-or-less objectively good, e.g. the instruments are in tune and the rhythm is in time, the vocals are well-performed, lyrics well-written, etc. That doesn't mean everyone will like it, but liking/disliking is subjective regardless of the quality of a given piece of music/art.
God is not dead, though some people are dead in their hearts/minds to God. The capacity to awaken to God is latent in the human spirit. It wouldn't be possible, for example, for humans to biology evolve to the point of being incapable of experiencing God.