In fact such amplification for non-structural components can be found also in FEMA P-1050 and NCEER formulation. See for example P-1050, Figure C13-3.1 formulation for "ap" as function of structural and component periods, where "ap" has a trapezoidal shape.
In both cases- Eurocode and FEMA- the target is to count two effects: one is the amplification within height range of structure another is the resonance with structure. In Eurocode the effects are kept in a single formula, in American literature they are separately presented.
It is preferable to work with story spectrum (if available) instead these approximations. I had an offshore case where in a lower deck the main effect was the third mode of vibration of the structure rather than the first one. But this was a special cases and usually what Eurocode and FEMA consider as amplification for non-structural components has physical bases and must be considered.