A lot of TV-shows struggle for getting a prime time on the channels. As a matter of fact, just everyone in the media industry is interested in broadcasting programs with the best ratings in the evening for the maximum audience watched them alongside with the most expensive commercials. Consequently, it is very likely that all alike sitcoms, comedies or crime series appear at this time because most people prefer entertainment after their working day. But we will never see educational shows about discoveries and scientific activity perhaps because they are targeted rather for children than for adults.
Practically, it is difficult for educational shows to get a good airtime on the TV. It happens rather due to the specific nature of these programs. Either politics or entertainment is appreciated by mass spectators so the media pays more attention to talk shows and comedies. It seems that the only way for scientific shows to get an airtime is to cooperate with the channels like Discovery which aim to enlighten topics of environment and science. Obviously, creators of scientific shows have to maintain high standards of quality so that broadcasters considered their content competitive enough to run it on their channel.
Funding of scientific shows is even more problematic issue than receiving airtime. Today producers have to be really persuasive in assuring authorities that their shows deserve a better financial assistance.