Sorry, I see every reason to illuminate the US flag if you choose to fly it at night. When that light goes out, it goes out for generations...at least until some future generation figures why it glowed so brightly, yet so briefly, in the history of man.
If you want an illuminated flag then arrange the light to come from above,in a way that doesn't interfere with your neighbors right to enjoy their property.
You can't(or shouldn't) expect to arrange your lawn sprinkler so the neighbors get soaked with over spray when they are in their yard.You can't(or shouldn't) expect your neighbors to put up with your love of loud stereos,power tools,or target practice with the .45 at 2 a.m.,well unless it is a burglar taking the stereo!
False patriotism that insists on annoying people with ostentatious displays doesn't impress me.The Nazis and Communists insist on in-your-face flags and symbolism everywhere.
Neither do I like seeing American flag napkins,and not really sure American flag t-shirts show respect.Sure don't want to see American flag underwear like the Union Jack shorts pictured on the British Marine in the Falklands;it just sends an odd message.