Wait....... People are actually saying Gai without Gates gets owned by Itachi and he can only beat him WITH gates???
Loooool, so the man who actually dedicated his entire life, paced himself around the village more than he owned half of NV, the Solo God, gets owned by Itachi in Taijutsu without gates? Yet Itachi chose to run away and told Kisame not to underestimate him. Not only that, Gai managed to create a Counter Sharingan technique in order to take down Sharingan users, avoid his Genjutsu and predict his movements.
Without Gates, Gai still solos Itachi. Give Itachi Sharingan and he still gets deuced. Give Gai gates mode and that's just pure overkill. Heck, let it be Gai vs Itachi bloodlust match and watch the whole planet get destroyed by the power of youth.