[mekoka]

I think you're taking things without knowing the details of his context. You speak to business in the language business understands. Sometimes business is not interested in your logical explanations. They're seen as excuses. Business dumps the responsibilities on your lap, gives you a budget, and starts pressuring you to deliver. The only conversations you then have are about time and money. Give me some time, give me some money, I'll save you more, etc. So those are the bottom lines of any arguments. Maybe in his specific case this (second) argument, of putting his job on the line to buy himself 10 weeks of work, combined with the first (staying aware of how the angular project is evolving and picking whichever comes first) was something that business felt comfortable risking. You would go in with all your React technobabble and be surprised when they roll their eyes and say "how long, how much".