[quantified]

Separation of data and algorithm is so useful. I can't really comment on how your senior is doing it, but in the area of numeric calculations, making numbers know anything about their calcs is a Bad Idea. Even associations with their units or other metadata should be loose. Functional programming provides such a useful intellectual toolkit even if you program in Java.

Sorry to learn, hope you don't get scar tissue from it.

[HeavyStorm]

Not sure how many people are writing programs with lots of numeric calculations.

Most programs in my experience are about manipulating records: retrieve something from a database, manipulate it a bit (change values), update it back.

Over here OOP do a good job - you create the data structures that you need to manipulate, but create the exact interface to effect the changes in a way that respect the domain rules.

I do get that this isn't every domain out there and _no size fits all_, but I don't get the OP complaints.

I currently think that most of the anger about OOP is either related to bad practices (overusing) or to lack of knowledge from newcomers. OOP is a tool like any other and can be used wrong.

[quantified]

Creating good reusable abstractions is not easy. It's quite possible to create tarballs of unusuable or overwrought abstractions. That is less of a knock on OOP and more a knock on the developers.

[Jensson]

But that is what classes does, it lets you have data lists and dictionaries implemented as a class so that your algorithm doesn't have to understand how the data structure is implemented. In functional programming the algorithm has to be aware of the data structure, I feel that is much worse.