If you understand only one idea behind every option price an investor will ever see, it is this: nobody actually has to look at a contract and decide what it is worth. Black, Scholes, and Merton's 1973 insight was that, under specific assumptions, the price of an option is determined entirely by the cost of manufacturing it from stock and cash — and that anyone who priced the option differently from the manufacturing cost would be giving away free money. Option markets are, in this sense, more like commodity markets than betting markets.

The market maker on the other side of your call purchase is not gambling on the stock; they are running a replication program — buying and selling shares in a precise, dynamic ratio dictated by the option's Delta — that, in the limit, manufactures the call at a cost they can compute in advance.