The reason for pushing people to pay at the pump is not all the sinister:
Just like with ATMs at the bank, self service aisles at the grovery store - the elimination of PEOPLE in business transactions. It is more expensive to have a human transact business than to have the customer self-serve.
The trend is everywhere, but not really suspicious. It's about business cost reduction.
Once that is the norm at the gas pump, expect a similar trend from ATM machines - charge the customer for the use of the machine. This changes what once was a business expanse (paying a clark to process your transaction), and then a no-cost transaction (well, the bank still charges the businee a transaction fee, but it's minor), to a revenue stream (like ATM fees).
And, yes Vurginia, the ATM was initially built to create a new revenue stream for banks. Charging ATM fees was always the plan, and the business analysis Issue Statement was not, "How do we make things easier?" but rather, "How can we generate more money?" The answer: find a way to charge the customer for each transaction, and the mechanism was the ATM.