Maybe in the essence of time spent, DL is the better way to go for most people but the fact there is another viable option is enough for me. The fact that HQ ilvl70 crafted gear CAN be dyed and have materia slotted into it is enough to make me want that over the DL, even if it does suffer in a few points of defense. (or whatever)

And honestly, crafting has been a totally different experience for me than it has for you apparently. I created an FC dedicated to help new players progress themselves and be prepared for end game and what's to come. As a GSM, I can absolutely give every member of my FC a new set of HQ jewelry appropriate for their levels, and the responses I get from them when they see their presents in the mail keeps me fueled to continue. Since my miner is the same level as my GSM (currently both 41-42 respectively) it costs me literally nothing but a few minutes of my time to make someone's day.

And in contrast to what one of the replies I saw, you can not and do not get jewelry to replace what you have through natural side quest progression. Some, yes. All? No way. Many sidequests will make you choose a ring for DoW or a bracelet for DoM and then you get no other viable choices. And to top it off, I craft nothing but HQ jewelry which is far and beyond the normal stuff in terms of stats. Those extra points add up when you have 5 slots.

This may all become irrelavant when everyone hits 50, but not everyone gets there at the same time. So what some of you may think as a waste of time, some of us also feel like it is a great part of the game that has helped us progress through to endgame.

To finally answer the question that the OP posed: Why are we doing it?

Because some of us enjoy doing it. Why should there be any other reason?