Not taking into account any manufacturer recommendations or SOPs, I tend to agree with your point - especially considering the massive rudder deflections needed with an engine out, there shouldn't theoretically be any problem in using normal rudder deflections on takeoff / approach. The airplane should be designed to be able to handle that, as long as you're not doing left/right full deflections with 300+kias.
Nonetheless, I never noticed any significant slip on the NG yet so definitely no need for rudder...will have a look next time I fly (so expect that to be in 5 years or so
)