(Exclusive?) use of FORCEINLINE

our devs are wondering (and are in fact having a lively discussion about) why in the engine, almost exclusively FORCEINLINE is in use. Besides this obviously ending up in platform dependent versions, some of them inline, some forceinline, we are asking ourselves what would be the reasoning behind such an aggressive inlining approach. On toip of that, it seems odd because MSVC should just ignore it anyway and make the decision about inlining the function or not on its own. Do we oversee something? Are there historical reasons for this?