You are gated from "new content that you paid for" the second you set foot into your respective nation. This is a game that is built around progression, gates are essential by design. Without gates you wouldn't have a sense of progress, and without a sense of progress you would be complaining that nothing seems worthwhile, and there's nothing to do.
This thread is not about "new players", that's just a straw-man. You guys just sound bitter about not being able to get into Ishgard with your crafting mules, and RP alts.
It's been pointed out time and time again that you will gain boosted exp from the story. What took nearly a month of consistent play to complete will now take at LEAST half that time. If you want your alts in Ishgard just power through it when HW drops. You'll even get some bonus exp from the level 50 quests.