You are absolutely right.
.......credit card companies may reject applicants simply because their history predicts they will repay their debts in full every month and that isn�t profitable. Yet it goes further. Credit scoring is used to build up the �right� customer base. It�s a �wish-list�, allowing them to weed out the customers least suitable for their business.
http://www.moneysavingexpert.com/cgi-bin/viewn ews.cgi?newsid1101485056,23650,
However, it won't have an adverse affect on your buying goods on interest free credit from stores, because the profit is already built in. It won't affect your ability to get a mortgage - lenders love long term financial commitments.
Credit card companies may start turning you down though. Although they get on average 2% from every transaction (the business who accepts the card pays it) that barely covers their admin fees.