It feel like we have here only few Oden fans here.
I can understand it though if people not want Oden here, for MY case I would love it, if Oda can explain it enough why not?
Oden in the war and him seeing Luffy/Franky, could became great stuffs.
Oden fan or not this would be bad writing from Oda, I don't why you and some others can even defend this horrible writing if Oden is actually alive. For what because you want to see Oden fight Kaido again and see him interact with Luffy, I'm sorry but that's not a great reason for wanting Oden to come back to life.
There are so many reasons why this would be bad writing from Oda, I'm too lazy to list them all but here are a few examples.
It would ruin Oden's backstory
It would ruin the whole point of the Scabbards
It would ruin Momo's character growth
It would ruin the whole point of Yamato trying to carry on Oden's will
And one of the driving forces of this arc which was to avenge Oden would be gone
So you and others would be fine with Oda tarnishing this arc, and ruining so many moments just because you and others want to see Oden fight in this war and interact with Luffy?
No matter how much you try to defend it and try to make excuses for it, this would be bad writing from Oda if he actually brought back Oden from the dead.