Why refusing customization is a fallacy

[Gilthas]

Again, in FFXI, people could chose what they want. That's why jobs were discriminated.

Or you tell me that if you go in Duty Finder 4-man as a DPS and ends up with a DRK, MCH and AST, you'll kick everyone or leave ?

Let me repost this and bold the part that you keep ignoring:

Having unbalanced jobs is bad for everyone. It's bad for the player that likes the job because he gets shunned from most parties, and it's bad for those who don't play the job, because they get stuck with an underperforming job in duties.

Bringing up zetas is a different story altogether. It's natural to expect that not all players will have the best of the best of gear. What you're asking for is to make jobs bad right out of the box.