Hey Zana. I've looked into this so here are a few thoughts.
1) You most definitly can be disfellowshipped for celebrating your birthday or your childs birthday unrepentantly.
2) Look up the history of this in the organization. it started its tenure under Rutherford, as did alot of other fun killing measures.
3) The bible NEVER forbids birthdays or even hints at them.
4) The two accounts (already mentioned), are the only two birthdays in the bible, and the way they put it together is that if the context was mentioned in a negative light, then because "all scripture is inspired of God for teaching, reprooving and setting things straight", then it must be in there for a reason.
At first i agreed of course. I mean these were bad guys (Pharoah, Herod) and they killed John the Baptizer at one of them. So sure that sounds plausible. But here is where the logic breaks down. INDOOR PLUMBING, is only mentioned twice in the bible, and bad guys had it (a king, and a false God). Do we determine that indoor plumbing is somehow wrong? Dogs are almost always mentioned negatively. Are dogs bad and a Christian should not own one?
To ASSUME the intent of the verses was somehow linked to modern day birthday celebrations, is just wrong.
5) Paganism. Of course this is the old stand by. Everything has pagan roots. Birthdays certainly share them. The candles and gift giving.....I don't even need to look it up I'm sure it was all about warding off evil spirits. Everything done in the ancient world was about warding off evil spirits.
Here however is the issue, and just for the record, there are plenty of fundamental Christian groups thatdon't like the idea of birthdays for the same reasons as JW's. The issue is that plenty of things JW's ALLOW, have equal pagan ritual.
Weddings are filled with them. A bouquet used to be heavy herbs to......you guessed it.......ward off evil spirits. White dresses? Wedding rings? I mean.....come on. How about wind chimes. Their origin is clearly pagan and they are allowed. Pinatas? Yep all good of you like them.
So the issue is inconsistancy. This pagan thing doesn't resemble the pagan thing it came from so its all good. This pagan thing seems to pagany to rehab so its forbidden still. It makes NO SENSE.
In the meantime, you ostracize your child, keep them out of key young social gatherings because of nothing......what good does it do? Are they really glorifying the child? Is it really pagan?
6) Early Christians didn't celebrate birthdays. Well......this is thought to be true, although not without doubt. Either way, early Christians did not do ALOT of things we do today. Culture and times have changed, and birthdays are not only for the rich, the kings, the man-Gods, or anything else. Why continue to force living in the dark ages behind Rutherford superstition?
Ok thats all i got.