Growing up as a JW and now raising my own children with birthday celebrations and xmas, I have learnt how important these celebrations and holidays are for forging strong family ties, not only immediate family but also extended family. I barely know any of my aunts, uncles or cousins because we never socialised with them, either because they were not jws or they weren't 'good enough ' jws.
The JWs, to my mind, are working in direct opposition to Jesus commands to love your neighbour. They'd rather preach to strangers, than save their own relatives. Many of them will do anything to NOT have to look after elderly parents or grandparents, including moving overseas to 'serve where there's a greater need'. No family ties for them whatsoever. They're married to jw.org.