To be fair though our telecom industry has improved since the monopolistic age of PLDT. But despite the breaking up of the monopoly and business running its normal course of opening the telco industy to other players (PLDT, Piltel, Extelcom, Isla, Globe, Smart, Bayantel, Multimedia Telephony, CURE, etc), market forces and corporate takeovers have resulted in 2 major players, Globe and Smart/PLDT. It's business without the social responsibility or just providing mimimally for compliance and yes, there is so much to be desired for specially if you compare other Asian countries to ours.
Looking at it from the business point of view and to answer "Why do we pay more for slower internet?" Because it is our choice... and if we want faster internet then the answer is simple... pay even more for faster internet.