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.