My sentiments exactly - some of the wonders are very situational - the colossus or lighthouse is awesome if you build it early enough with 2 whales, crabs and a couple of fish! Couple that with God of the Sea and you have a monster city fast - production and population.
The Great Lighthouse doesn't have any tile effects - it just gives you a free lighthouse as well as its effects on unit movement/visibility.
As mentioned, the Colossus is somewhat more situational than most. Petra is situational, but (a) has better payoff, and (b) if you have some desert around, you usually have a lot, and assorted different tile types to go with it. Sea resources are great, but you don't get any equivalent of hills or flood plains to add the bonus to, and even with the Colossus sea tiles without resources are relatively mediocre - you don't really want to settle cities with large expanses of open water, certainly not early in the game.
I think growing your cities is important, BUT I have my reasons for not building the HG.
1.) I don't like getting Mathematics very much mostly due to not conquering much in the early game.
Mathematics is required for Currency, and going for Currency and then Guilds is important in any early game. And simply going for Mathematics for the Hanging Gardens rather than Courthouses or Catapults is perfectly viable. It's not on a particularly awkward tech path - indeed it comes just after Construction, which is important defensively (Composite bows) and for early expansion (Colosseum).
2.) I can get more good stuff by allying with a Maritime CS.
Now there are five CS types in the game, you can go full games without having any CSes of a particular type, especially on small maps. They tend not to start offering quests straight away, and only intermittently after that in the early game, so relying on both finding an early maritime CS and getting an alliance for long enough to be helpful is a gamble. Sure, if you do get lucky, you might not build the Hanging Gardens. You might not build Stonehenge if your closest neighbour is Wittenburg either. Then again, what's better than +3 food in the capital (maritime CS)? +9 food in the capital...
3.) I can always go Tradition to get some nice growth bonuses.
4.) I can always built Granaries and other food/growth buildings.
Both of which make the Hanging Gardens stronger, and vice versa. In my last game I had Hanging Gardens, Tradition, all the food/growth buildings (all four, note - and you have to wait until Biology to get the second-tier food building), Fertility Rites and Swords into Plowshares. You might as well argue that opera houses are bad because you can just build extra amphitheaters or ally with a cultural CS.
5.) And lastly I don't like growing my cities too much in the early game. I much prefer to expand early and build and army to defend my new cities and grow them then.
You know what helps with that? Being able to work your production and gold tiles - as many as possible as soon as possible. Even if you don't want to grow extra citizens straight away (which in my opinion is bad practice even for wide strategies, since you want the capital to be large and productive ASAP to spam settlers and units, or make enough gold to buy them; and 6 food = 6 production when you're building settlers), the Hanging Gardens feeds 3 of your citizens without them needing to work any food tiles at all. There really isn't a scenario I can see where this is not a very strong early Wonder - in the early game it's only rivalled by the Oracle for versatility and Petra for its ability to set you up with a potentially game-changing long-term advantage.