What you’ve described to me looks like a 100% positive outcome and giant reason why p8 online is needed. Except you’ve misjudged one aspect:
Wrong. Running with others in TZ and Baal for EXP gains would be well worth it. In these scenarios FFA drops are more fun and exciting (it’s still better than solo in p8), and your EXP rate will still increase; 8x stacked characters clearing vs one.
The only things which REALLY discourage team play are pickit hacks and controller vacuums. If Blizzard would take regular action against cheaters then there would be no issue.