I've found overcommit useful for some scientific computing applications, but you're right it's not the most intuitive default. You can disable memory overcommit on Linux for the same behavior as Windows, if you want.

https://www.kernel.org/doc/Documentation/vm/overcommit-accou...

Also, I found this post that suggests Windows technically does overcommit memory, but only for stacks(‽): https://superuser.com/questions/1194263/will-microsoft-windo...