Players refuse to take my preferred move instructions?

It seems like, more often than not, my better players tell me that they don't think their game will benefit when I tell them I want them to learn a preferred move. It doesn't seem to matter whether I use either of the responses (I think I know better or I want you to try) when they refuse.

Tips?

What are the ages of the players?

What sort of things are you asking certain types of players?

I get about 80% of my requests agreed as they tend to be requests to young players and they will be suited by the new PPM.

To add to what bigdanio wrote, i normally only ask them to learn PPM's after being at some time on the club and they are on my favoured personnel(takes a lot of sucking up to them!).