Why is there a question mark after Kopech? He's 21, pitching in AAA, throws 100 mph, developing his change-up, and is being coached by White Sox instructors and coaches.
Rodon was being developed. He was drafted by the White Sox. He got hurt, and it seems to be a bad injury. What do you want them to do? Magically medicate him back onto the mound?
As for Shields and Gonzalez, you do realize that in a rebuild (or TANK!!!, as you call it), there are slots in the rotation where vets, usually crappy ones, have to eat innings right? The bullpen can't be called on for 4-5 innings every night. Furthermore, the young guys, like Kopech, are typically on an annual innings limit, so someone has to pitch those innings. That's what Gonzalez and Shields are supposed to do.
If Rodon was healthy, they would be "developing" 80% of their starting rotation + the best pitching prospect on the planet. What more do you want them to do?
There's also service time issues, and while I'm not as well-versed as I wish I was in this department, I'm sure some far knowledgeable posters can educate you on this, if you're wondering why there aren't young guys in the 'pen and why Kopech still isn't up (which again, besides service time, he still needs to develop his change-up).