AFAIK:
Reduced wing root bending moment therefore reduced wing mass reqd.
Provides anti wing flutter mass balance.
Easier maintenance and engine change.
Safer in event of fire or catastrophic failure.
Even read somewhere that interference drag was demonstrably reduced
cf fuselage mounting I guess but defo leave that to the wind tunnel chaps.
Don't forget range of cost considerations in construction and operation.
OTOH have you looked at the little waterspout under B737 fans on a wet taxiway?