I'd say Tamahome is more popular because 
he is the original. He has the power of Suzaku 
but Taka does not. And Taka is much more 
mushy than Tamahome. I love the fact that 
Tamahome gets extremely po'd at Miaka for 
the way she reacts to Nuriko's death. And this  
even after they (Miaka/Tama) have declared 
their love for each other how many times??? 
Tamahome does make an appearance in the 
OVA's, but he's depicted more as a bad guy. In 
the end, Miaka chooses Taka and I was 
dissapointed by that. I think Tamahome has 
more character.