I grew up with pasteurized milk. As an adult, I tried unpasteurized milk. The taste is different, was a bit weird at first. After a couple of glasses, I much preferred it over the kind I grew up with (it's just so much better), and it's all I drink now. Normal pasteurized milk tastes like low-fat now (i.e., it tastes like drinking water from a glass that had a little milk in it already).
So I don't think it's quite so simple that everyone always prefers what they grew up with. But you're right that we often need to get used to new kinds of food before we accept it.
Of course our animal accommodations and milking practices were much cleaner than what one might find at commercial scale. But that's not a problem inherent in raw milk, but rather the same unsanitary conditions that plague the industry at large.
Take a pint of fresh-from-the-cow milk and a pint of your typical store-bought pasteurized milk and leave them open on the counter for 2 or 3 days at room temperature. The former will turn into a tart, pleasant smelling mix of curds and whey I'd be willing to taste and possibly consume while the latter will be a smelly, gag-inducing spoiled mess that will almost certainly make you ill.
I've witnessed this first-hand.
Raw milk is loaded with beneficial bacteria that can be naturally culture itself to various ends, more often then not out-competing environmental bad bacterial. Pasteurized milk, devoid of most bacteria to start, will (most often) be overrun by bacteria that will make people ill. I does not surprise me that our "normal" milk is a non-trivial vector of food-borne illness.
Importantly, people are more likely to die from food that looks good but can kill them than they are to eat food that looks and tastes nasty.
If your milk is over 72 °C for 15 seconds or more then your pasteurizing it even if your starting with raw milk.
For the record, I don't live in the US, and here they don't pump cattle full of antibacterials. I buy my raw milk at the grocery store, it's legal and vetted by the health authorities.
Also, yes, it is addictive levels of goodness. :)
I lived the first 25 years of my life in the UK and drank pasteurised milk almost exclusively and found the taste of UHT to be lesser.
I then lived in Poland for two years and drank UHT only.
At first I disliked the taste of UHT but over time I grew accustomed to it.
I am still able to tell the difference between pasteurised and UHT, I just no longer mind.
I find that for many things in life where there are similar but not exact variants, one tends to prefer the variant one first tried despite both variants being potentially equivalent.
Pasteurised milk vs UHT is one example. Margerine vs butter is another (I was raised on margerine and disliked butter for years). Windows vs Linux desktops (again, I was raised on the former and initially disliked the latter despite both being generally logically equivalent).
I have since learned to be more accepting of the differences in variants of food and tech. This seems to make life easier for me.