The fear of being disfellowshipped is the fear of being rejected and totally excluded by everyone that knew you from the time of your birth, including your family if you were a born in. As you were encouraged not to have bad associations (the rest of the world), it amounts to being rejected and excluded by your closest friends and/or even family members.
And that could come only from voicing your disagreement with a policy they enforce everyone to follow, or after somebody stalked you to find out who were you spending the night with, or after you decided to wear a cross pendant or decorating a Christmas Tree in your own house. A very high price to pay compared to the “crime”.
Nobody views their baptism as a commitment to a human corporation in any way but as the public expression of their private dedication to God. Adults don’t understand what they are getting into, children much less so.
They say the day of your baptism is the most important one in your life, even more than your wedding day, a child is in no condition of making such a big commitment. Neither an uninformed adult that doesn‘t know the implications of entering into a contract with the WT. Nowadays there is more information available, years ago it was not so much around.
Their baptism is a fraud as it has a different meaning for them than what it has for their followers.