Почему перед telly нет артикля???

From Longman Dictionary of Contemporary English:
-TO BE ON TV - устойчивое выражение. Хотя, в принципе, употребление артикля THE допустимо. Но, как правило, в реальности его не употребляют.

- What’s on television tonight?
- Later that evening we watched it all on television again.
• They arrived together, dressed with the studied perfection only achieved by gangsters and people about to appear on television.
• Keep your eyes peeled for policies, they don't show up so brightly on television.
• He accused witnesses of fabricating sensational testimony just to get their faces on television.
• He had seen her on television.
• For years the central axiom of modern campaigning has been that elections are won and lost on television.
• Viewers come to feel they know the people they meet on television almost as well as they know their friends and associates.
• Naptime was from four to five, and then he watched the evening news on television in the recreation room.