Not to mention this game is terrible at inventory management for alternate characters (since you cant mail to your own alts).

Also, they specifically marketed this game as a 'do it all on your main' kind of game. Where alts are a little more of a cosmetic feature, not to mention a lot of people have the discounted 1 player per server sub (which further reinforces this design philosophy of do it all on your main).

The myth lockout is fine as it is, and it gives you a choice of a 'main class' as well as allowing you to funnel myth tomes how you want (say run WP on a tank class and gear up your 'main' dps class). For coil though, it would be so much fun to be able to play with another group on a different class. Coil lockouts should be job based, where I can go in with my static as a PLD and then later on in the week if i'm bored or someone is asking I could go into coil as a DRG or BLM and take a shot at some dps loot maybe, but mostly just experience the content in a different way. This would also promote the social aspect for many people, as they would finish coil on their static and then run with other people on an alt class. If they are truly worried about gear bloat, maybe limit loot lock to something like 2-3 jobs per week. So you can go in with 2-3 jobs and get loot and then be loot locked if you run with any other jobs.

In the end, instance locking has always been a poorly thought out mechanic that is very anti-MMO (it doesn't promote social interaction between players). Its a large reason why many end-game MMOs continue to fail at making endgame content. Loot locking is not a new concept, maybe the devs here can consider not copying WoW for just this one thing.