I see your point, but every other subscription game once you max out your storage your done. Square Enix is giving you inventory + 3 retainers. Thats a lot more space then WOW gives you for free. You can do what people do on other games. Start a guild and use guild storage for space. Have alts and use their storage and retainers for storage. Thats the alternative that you get with 99% of the other games you offer. No game gives you unlimited storage.

Im personally happy to pay 2 dollars a month per retainer. Its nice to have an extra miner and botanist running around for me.