I speak from several years of personal experience with- and without the use of mods, all types of mods, and even some personal experience with LUA coding. I see why people are concerned but I strongly feel it's being way overexagerrated, and I hope that when it comes to the implementation of UI mods, SE considers the possibility of overexagerration. I feel that FFXIV should be made as an evolution of the genre, and that they should implement what they want and with appropriate moderation, the reception should be mostly positive.

FFXI was not built with mods, and it in turn led to people using things such as windower scripts and ApRadar, these things were terrible and I am strongly strongly against such things. By allowing the use of UI mods, they gain the ability to moderate them and choose what people do with them. When you don't give people an in house option, they will use third party options that will be even worse, and SE wont be able to moderate these things.