New membership cards?

We noticed that the new membership cards now state how long you have been a member of the CC.  Why has this been added? 

Do new or perhaps long term members get preferential treatment according to the length fo membership.  Surely it is our personal business how long we have been members of the CC?

Ours state 4 years although we have been members for 8 years however we had a 2 year break in between as we were on a seasonal site.

I really don't think thsi information which is personal to each member shoudl eb displaye don a membership card as after all your Credit Card does not state how long you have been using it!