I guess their growth strategy was mostly about hiring every Finnish person, or living in Finland (and then in other countries) with a PhD in some quantitative topic and then market the "we have xx PhDs as a consultancy for all your projects". So you probably are right that not all these are needed anymore?

Why Finnish and not American or Persian?

Finnish company

AMD is (according to their own statements) in the process of picking up a lot of software manpower. And wages in Finland are European tier, not US West Coast. Why lay them off?

Because nobody has been fired or fiscally punished for firing excessive number of people? :) People are notoriously bad at predicting potential positives, so firing people means nobody can prove that something wasn't created. In reverse it is possible to blame people for overhiring because that can be supported by hard numbers.