i think each organization has a different reason as to why they do or do not use the word pledge. i don't think it is hazing to use the word. it does seem that many use the word in a derogatory manner, meaning they may something like "he/she's JUST a pledge," like a pledge is not worthy of respect or something.
i look it at this way....you make a pledge to the organization; it's something you DO, not something you ARE. we have a pledge ceremony, just do not call them that. we use new member because they have been invited into membership and it is possible that they will not be initiated, but we do not hold that over their heads. it is also possible for initiated members to lose their membership. either way, if you are not meeting the standards of membership, you can be kicked out, new member or not.
not aruging, just throwing my thoughts out there.