Why wouldn't one compare apples to oranges?

It’s just meant to mean that the two items are in completely different categories. That you shouldn’t have the same expectations for both, because they are quite different by nature.

My border collie died.

I bought a new puppy to replace him.

She will never be the dog that Michael was.

It’s like comparing apples to oranges.

This is an excellent question. My mother feels the same way and so has coined the term “comparing apples to sofas.”

I have no proper answer for you.

They are both fruits.

Your argument is invalid.

Which is better: the 1967 Mustang or “2001: A Space Odyssey”?
Which is better: Baseball or a Silverado Vineyards 2006 “Fantasia”?

Completely different things.

Things that are different are different. When you talk about how starbucks is closed and that sucks and someone else talks about how they were raped yesterday and some third person is trying to see how equal those experiences are, they’re comparing apples to oranges. That’s, however, provided with the assumption that comparison is about equality which isn’t your assumption. In your assumption, we can compare apples to oranges and say they’re different and move on.

It took me six answers to understand it Thanks all! but @Simone_De_Beauvoir, thanks to your clear explanation now I completely do!
Move on it is.

Well, apples are round. Oranges are round. Apples are red. Oranges are red with some yellow in them. They both fit in the palm of your hand. They both grow on trees. They are both fruits. They are both tangy-sweet.
Hmmmm…I go with JilTtheTooth’s kid saying that her mom uses the term “comparing apples to sofas.” Much better! :)

I mean, why would I want to compare an apple to an apple (or a BMW M3 to a BMW M3)...., nothing spectacular would come out of that surely?

That depends on how much variation there is within each category. Individual BMW M3s are probably very, very similar… so there is not much to be gained by comparing individuals. But individual apples come in a variety of shapes, colours, sizes, and flavours – when compared with each other. Comparing an individual apple to an individual orange, on the other hand, would just tell you, “You have an apple there”.

That is only your assumption @dappled_leaves!

@Dutchess_III You have a point. I have never actually compared individual BMW Ms; perhaps they come in different flavours as well!

Here goes. Let’s use education, specifically traditional public schools vs charter schools. Both are in the business of educating children. Both use classrooms, and have similar aged children. Some say that charter schools are the way to go, because some studies have shown that students from charter schools perform better on some standardized tests. I won’t get into the validity of the studies… let’s just assume for the sake of this post that charter students do perform better.

One might think “Of course we should use the charter school model… the students are doing better”. However, that conclusion ignores many important facts. For example, every student in a charter school has requested and been accepted to attend a charter school. While public schools must teach every child within the district regardless of the child’s ability or willingness to learn (or even attend). So yes, they are both schools, just like apples and oranges are both fruit. But when you look more closely, you notice that they are not the same.

There’s more to contrast than compare.

Dutchess III almost nailed it. And apples to apples? Eat a Honey Crisp then a Roma. Cook with a Roma then a Granny Smith. Eating a raw Roma is like eating paper maché. Granny Smith makes great pies & goes with rhubarb crisp, but nothing beats a baked Roma with stick cinnamon and a dollop of hard cream at Christmas. Dutchess’ point about some similarities alludes to this: choose the apple and the orange sez, “Close, but no cigar.” The apple is left with, “Well, Oh, Yeah!? Nothing rhymes with orange!”