Why kiss the Blarney Stone?

The legend goes that when you kiss the Blarney Stone, you are give the gift of "gab" or speaking with great eloquence/flattery. The meaning of "blarney" as "flattering" first derived from Lord McCarthy and Queen Elizabeth I. Elizabeth wrote McCarthy to request an oath of loyalty to her as she was going to reoccupy his land. McCarthy wrote back with respect to her, saying that she was welcome anytime she wanted to escape to Blarney, but he never answered her completely. The Queen wrote back thanking him for his offer, but still asked for the previous orders; McCarthy again ignored her letter, respectfully offering her a place to stay. After going back in forth a few times, Elizabeth finally responded to Lord McCarthy saying he was giving her a "lot of Blarney", thus the tale was born. Is that true? I don't know, but I hope so because it's funny to me. But who wouldn't want to have the chance to maybe gather a disease from TripAdvisor.com's "most unhygienic tourist attraction" by kissing the stone along with the other millions of people in the world? My older brother Chris kissed it a few years before I did, do you think that counts as incest? yikessss