ecc989b1_Tips_for_Parents__Remedy
[0] 3 [Cause / Symptom] Parents do not attach much importance to their children speaking Tamil. [Possible Reasons] Parents feel that as the kids will live in the west, it does not matter if they do not know Tamil. [Remedy] 
As a practical matter, this may be true. However, this implies a conscious rejection of one's roots. Language is one of the basic characteristics that make up one's own image of who he is. If one were to extend this logic, then most of what we follow - dietary habits, cultural behaviors, religion, and other value systems - can be discarded. There are many groups living in various regions of India other than their own but still maintain their traditions including language. (e.g. South Indians in Mumbai, Telugu's in Chennai and elsewhere in Tamilnadu, Saurashtrian's in Madurai, et al). The second and future generations of these groups speak the local language outside but still speak their own language at home. Thus, in my opinion, parents should make an effort to encourage their children learn Tamil.
Tips for Parents
Remedy