Probably because the secular liberal media don't want you to see that it actually happens from time to time in this country.
And, (prepare to be horrified) I couldn't possibly care less if somebody somewhere burns a American flag they've purchased and that they own, in an area where public burning isn't prohibited, or on their own property. I'd prefer that they didn't - that's why I'm against the amendment, because nothing will do more to cause flag burnings in this country than it being prohibited.