In point of practicality - insulin does have differing utility for each diabetic.
A note I meant to put in the original comment is that utility is considered equally, not equal. So yes, if you have 100 insulin pens they distribute according to need.
The point of the original wikipedia article is it is normally always possible to construct a "utility monster" that would take the need to the extreme and suck away all the utility.
In the diabetic/insulinpen scenario this might be done by declaring the monster is a giant of epic proportions and failure to take all 100 pens means death, whereas for the others it 'only' means severe complications.
It should be noted the point at which insulin is next available alters the practicalities but not the gist; if people will die before more insulin is available, our monster should have more utility than those who die etc.
One way to frame the egalitarianism of utilitarianism is as a part of the equity vs equality debate; considering everyone equally but not as equals is fairer.
Whether you're talking about utilitarianism or microeconomics, your utility function has to take those things into account.
If you use a statistical average model to distribute resources you'd end up with a very unhappy population.
Did you never do the experiment in school where you randomly distribute candy, calculate the class average utility score, then allow people to trade and calculate it again?
It's always much higher after trading. Trade creating value is one of the central tenets of economics, and it's based on the concept of utility heterogeneity.
I was not advocating nor (intentionally) suggesting utilitarianism meant everything identical for everyone.
Hum... Yes. That's still in economics 101. Everybody will still be better off after the trade. Also, it's very likely (but still dependent of the candy distribution) that everybody will prefer to trade with that one kid instead of everybody else.
If you had, for example, 10 treatments for a disease, 10 severe cases, and 10 mild cases, I would assume that utilitarianism would posit that the 10 most severe cases should get it.
You could maybe say "insulin is an urgent need for a diabetic who just ate 3 cookies, but not as urgent for one who just ate a plate of vegetables". But both will need some amount of insulin within 24 hours.
Type 2 is a different story, and not all Type 2's need insulin.
And there are people who want to live in the woods without interacting with people, with 0 use of $100. And people who don't like cookies at all, etc, etc.
I view it more from a statistical point of view. Your model doesn't have to consider individual preferences (or needs) to increase utility (it would have to to literally maximize).
We can likely assume that out of 1000 people, 100 insulin pens would have more utility being distributed to the ~10% diabetics, rather than the same diabetic who "wants it more".