Nubios
Nobody would lose something that they already have - it is just that the extra goodies available through one guild may not benefit them as much as the extra goodies from some other guild.
Neutrals in aligned guilds would lose either their neutrality or their friends. I chose a group of players that I like being around, not a faction. I am a Rift Walker. I don't fight for the glory of Jena, but for my friends ... even those who are not Karavan-aligned. If others chose their faction before they chose a guild then they are different from me. That's not necessarily a bad thing, but I would appreciate it if any such changes accommodated those like me as well as those who are motivated more by factions than by friendships.
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Do not assume that you speak for all just because you are the loudest voice; there are many who disagree that simply have no desire to waste words on you.