I think most people would be okay with an exit tax if it's reasonable. Requiring the owner of a business generating €20k in profit to then pay €70k in taxes is not reasonable.

Canada also has an unreasonable exit tax. Canadian founders are taxed on 50% of the FMV of their shares on departure. So if you own half of a company that is worth $50m, your taxable income for the year of departure is increased by $12.5m.

Agreed. As mentioned in another comment, I think it'd be fair to levy the exit tax when you actually sell your company in the future. Like, if I ever sell my business, I'd be happy to pay my fair share of German taxes on said business, even if I'd no longer be a tax resident of Germany.

The current implementation which essentially simulates a "virtual" sale of your business once you leave the country is pretty terrible, as most normal humans don't have that sort of cash on hand because, well, they actually didn't sell their business at that point in time.

Interesting pointer on Canada - thanks!