The worry is:

• the german government prints 1bn euros and hands it out to the people
• the people will spend 300m of it to buy furniture, cars, smartphones
• that money goes to companies abroad, to billionaires abroad, and can't be "taxed back"

The solution is:

• literally create import tariffs that make importing goods from other countries more expensive, so people are incentivized to spend money on domestically produced goods
• now the money flows back to domestic billionaires,
• where it can be "taxed back"