German credit scoring institutions collect data on behalf of banks, insurances, etc., and you need to consent that they send data to the credit scoring company. So you are actually consenting. If you never give consent to any such party, the scoring company must not store data about you (and most probably won't, they are tightly observed by data protection agencies).
It will become interesting with GDPR, when customers start to revoke their consent to exchange data with credit scoring companies.
It will become interesting with GDPR, when customers start to revoke their consent to exchange data with credit scoring companies.