When you write silly things, people are going to be condescending.

If your response to capital flight is "well, one day other countries will raise their taxes" and then when asked go into a semi random rant about trump, well, those aren't responses particularly worthy of consideration etc.

It is fine to just say "huh, I hadn't thought about that." Or "I'm not sure, I haven't read much about this."

Edit: e.g., in the article I politely linked earlier, you might've noticed that the French waited 15 years without that return of capital:

That led to thousands of rich French families to move to countries such as Belgium to avoid paying the tax, including most famously 'Green Card' actor Gerard Depardieu and members of the Mulliez family, owners of the Auchan supermarket chain.

Prime Minister Edouard Philippe has estimated some 10,000 people with 35 billion euros worth of assets left in the past 15 years.