I've played many MMOs over the years that have started off with and without cash shops, seen the same arguments and insults being flung back and forth (x is lazy for wanting to pay/ x is jealous that they're too poor to buy y) and I've seen the slippery slopes of cosmetic only cash shops start working in "harmless" in-game things such as potions and teleport scrolls. Most of these go on to become the typical gamebreaking cash shops that sell gear protects, statted costumes, special gear enchantments, and so on. Granted, most of the time these were f2p games or games that started off p2p and gradually went f2p. This led to alot of players quitting and those who initially defended and flung insults in the name of the cash shop crying because they had barely anyone to play with. Granted, I don't think FFXIV will ever go f2p as SE has shown their devotion to the subscription model through FFXI but a good deal of people that play this game play it because they believe that in paying up front they should be able to access everything the game offers without being forced to pay more for it. Sure, these glamour items don't really impact my gameplay and I personally haven't bought anything from the cash shop as none of it interests me and my in-game glamours are fine as is. But the point of a p2p model is that you pay up front so you aren't forced to keep paying microtransactions for various things. I'm fine with there being cash shop shortcuts to glamours as long as they're available in-game as well (exceptions being the korean/chinese outfits that those players also had to pay for) but the notion of exclusivity and being forced to pay more on top of what we already pay to avoid said paid exclusivity starts looking alot more like the f2p microtransactions people despise.

Tl;dr A cash shop shortcut for those who don't want to work for it is fine to supplement income, exclusivity unless special cases (korean/chinese outfits) is not.