Ill tell you why its wrong. Bc we should only look at our gedolim like he looks at the actors! Our Gedolim our the ones who we should be wanting to get autographs from! They are the EMET. and the actors represent nothing but sheker and immorality. Basically what you are doing is agreeing to the actors morals and values by idolizing them and OOing and Ahhing thaem bc what he does for a living is immoral and stupidity and brings nothing but impurity to the world.
I used to have the same issue, i saw a famous person and was like AHH! But now as i grew in judaism i realized the emet and whats real and starting looking at the goyim like celebrities. Theres no better feeling now to see a famous Gadol and try to get close to him or get a beracha from him.