Why is it so bad? It is completely useless, compared to an easily mass producable howitzer (spelling incorrect I presume). It has a little bit higher base strength than a howitzer, I give you that, but with 10 refined mana, that's...insignificant, a howitzer is just as untouchable. I'm not sure whether it takes longer to build than a howitzer, but I can usually build them in one turn, and I can only build one at a time (in a capital with 2000 hammers per turn...). And the end result you get for building the Goliath? A tough but unusable unit that gets 100 xp for free (and is likely to never go much past that). Howitzers get lots of xp every turn from their ranged attacks. It has 2 moves, 3 with mobility I, the same as a howitzer. It cannot learn to use enemy roads, howitzers start with this ability. It can bombard cities, but so can howitzers. It can attack once per turn, either melee or ranged, and can never learn blitz, which the howitzers get for a birth gift. Interestingly, a relatively high movement unit cannot get blitz. Even buying the promotions to increase the damage cap for ranged attacks, I have yet to see Goliath kill off even severely weakened enemies. My howitzers are more than capable in that, especially in stacks of ten or more. In fact, I have cleared heavily garrisoned cities in a single turn. Come to think of it, even crossbowmen are more effective in wiping out enemies. Resident machine spirit is a joke, the machine spirit pops rarely and has a whooping 50% chance to go poof every turn. And a tech priest can reliably give it to any number of howitzers at once. 1 att and def for strength 18+ unit, holy crap I really must have it? 33% more movement, still no more attacks or enemy roads. Ok, machine spirit is nice for howitzers; for Goliath, it's just sad. Both howitzers and Goliath heal slow and never on the move but fortunately adepti can reme...repair that. The only perk I can think of the Goliath might have is that cavalry cannot flank it.
Interestingly an end-game hero is likely to be the weakest link in any stack it occupies, that is, if I bothered building it anymore. What is its supposed role? Defending my already untouchable capital (200% fortification, palace guardian, lots and lots of crossbowmen and howitzers)? It certainly cannot go with an offensive stack; I'd never get anywhere. I just cannot think of a reason to build Goliath over yet another howitzer under any circumstances. Even given a choice between a free Goliath and a free howitzer, I'd take the howitzer. Goliath just...fails.
Interestingly an end-game hero is likely to be the weakest link in any stack it occupies, that is, if I bothered building it anymore. What is its supposed role? Defending my already untouchable capital (200% fortification, palace guardian, lots and lots of crossbowmen and howitzers)? It certainly cannot go with an offensive stack; I'd never get anywhere. I just cannot think of a reason to build Goliath over yet another howitzer under any circumstances. Even given a choice between a free Goliath and a free howitzer, I'd take the howitzer. Goliath just...fails.