Kanwardeep Singh Ji,
'Sikhi on the decline in UK' I am not sure - Please Visit Soho Gurdwara Birmingham - I was pleasantly surprised. I wont go into details unless you specifically want but the question may be the deffinition of sikhi and context.
You may agree that we in UK have enough to exist on and we know it i.e. we are probably satisfied with the reward we get for our labours. In Punjab this may or may not be the case. There the example is set not by rules and regulations but by greed in the most.
I beieve the reason for this is that we have made our religion far too convoluting that we have lost the basic message like being true to yourself and to the Lord, not hurting people, helping the needy, share your wealth (that includes knowledge and resources)
and so on. I believe reading the Granth Sahib for people like me (I am sure there are thousands like me) does not help me become a better sikh (I do not understand the language used)- it may fool people outwardly who may think that is (being guru ka sikh) better than following and practicing the basics. These basics are very difficult but very rewarding - remember Guru Nanak did not have Guru Granth Sahib - he practiced these basics
!Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/hard-talk/33251-willing-die-not-convert-islam-but.html
So if by becoming westernised you mean following the basics more than pretending to be 'readers of Granth Sahib' may be you are right.Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=33251
I think our children (in fact all) should be educated in these principles and they will soon look for enlightement in the Guru Granth Sahib to bring 'Sikhi' to the fore again.