With the introduction to Jewellery Crafting, and it being locked behind a pay wall, I can see both sides to the argument. I have also come up with some ways ZOS can keep the Jewellery crafting behind a paywall and also have it not be P2W.
As we know, if you buy the summerset chapter you will be able to use the Jewellery crafting station, this means if you don't have Summerset you will not be able to obtain traits other than healthy, robust and arcane for non crafted jewellery, via transmutation, if ZOS was to allow all players to refine, Decon, improve and research their jewellery then this will remove the pay to win feature but keep pay for convenience because you still couldn't buy Shackle Jewellery but can still buy. This allows for the entire player base to be on the same level with any gold jewellery and trait.
You could even make the skill line only available to Summerset so people without the chapter would have a harder time researching the traits, deconning and refining mats as well as not being able to get 100% chance of improving Gold jewellery. This would still give a nudge to buy the chapter (what ZOS wants) as well as changing P2W to Pay for convenience / less gold mats