You are right brother but practically sd channels exist due to many factors-
Low Price (customer and broadcasters friendly)
Low bandwidth (operator friendly)
Content ( some content like old movies ,songs are not yet upgraded to HD so no option)
Even if we ignore 1st and 2nd point, 3rd one is the most critical one there will be too much cost to upgrade existing sd content to hd but they could also simple upscale however it won't improve the picture quality other than the logo. Plus govt you know , they try every possibility to squeeze out money from companies/individuals , so broadcasters will end up paying huge amount plus it might require extra satellite/tp to broad those channels as bandwidth usage will increase.
Offtopic: I saw some old movies where the concept was hafta wasooli was present and gundas used to collect it, modern day equivalent is our IT department and govt ..old wine in a new bottle
