no, its not DotA but its very much inspired by it. we can have differences of opinion and neither one of us is short sighted.
the abilities do stay competitive throughout the game. when i play Torch Bearer i make sure to get my Fireball up to rank 4 every game. by level 15 its no longer my best source of DPS but it has a huge amount of utility in outranging towers and finishing runners. regular attacks can't replace either of those functions. all kinds of direct damage abilities are good like that, they're still somewhat useful even after regular attacks start outdamaging them for pure DPS.
and for what its worth, i could easily reverse your argument and say "you shouldn't trivialize passive abilities that boost Weapon Damage by emphasizing direct damage attacks too much with special equipment." Why shouldn't it be legitimate for a Rook player to focus on God's Strength or an Unclean Beast player to focus on Beast Within?
that type of argumentation is circular and goes nowhere. i'm not looking to turn this thread into one of those infamous last man standing internet filibusters.
all im saying is that i don't see direct damage abilities as being deeply flawed to the point of needing an overhaul of the game's equipment system. they are what they are, and very useful at that. like any game there are various gameplay dynamics that affect the relative utility of one thing vs. another based on current game conditions. the dynamic between direct damage (best in the early game) and regular attacks (item dependent, therefore best in late game) is just one example of this. it adds variety. i like it.