I wouldn't say 35points is 'slightly' below it's Sp.Att, it's a pretty big difference.
But the main problem is Sceptile only has 2 STAB physical moves, Leaf Blade & Dragon Claw, (I'm not including Dual Chop), which both fall well below expectation compared to it's Special STABs, Leaf Storm, Dragon Pulse & Giga Drain.
Sceptile can also make good use of a Giga Drain/Toxic set.
Basically, it's just built as a Special Attacker.
With all that said, it's not impossible to make use of a Physical Attacker, the suprise aspect of it doesn't really make that much difference unless you're predicting a Sp.D wall/staller but it does have Earthquake & Swords Dance in it's arsenal.