Well, the egyptians still get 2 research from all sea squares, while, japan gets one less food (on some tiles 2) AND one less research from the desert.
Also, the reason you've had few deserts is most likely because you haven't tried placing cities near the ones that are there (why would you when playing someone other than egypt?).
The desert bonus is way more powerful than the japanese sea tiles, seeing them tile by tile. When you take into account that there are more sea tiles, I would say that it it quite hard to differ between them. It all depends on play style, and how good you are at utilizing the bonus.
Wow you've got me all figured out.
Actually I play every civ. In fact I exclusively play random and HAVE gotten Egypt many many times, and also gotten Japanese many times, along with all other civs.
I have also played Civilization since I was 9-10 years old, and been playing ever since, even buying an xbox just to play civ rev - So optimal city placement comes natural to me: but thank you for your concern regarding my egyptian city placement.
Could we say the same about you? Here's hoping
Now lets get to the issue rather than persona:
Egypt gets +2 resource bonus on desert as one of their civ bonuses.
Japan gets +1 resource on sea.
In order for egypt bonus to equal japan, for every 2 sea squares a japanese gets, an egyptian needs 1 desert.
Now we know for a fact that pre-courthouse coastal cities get 3-4 sea and post courthouse they can get 8-10. And there's no way to match that much sea area with desert area, even if you're only looknig for 1/2 the number of tiles.
Then we look at the start of game - here a sea square is exactly equal to a desert square, so for those bonuses to be of equal value, you'd need a desert tile for each sea tile of the japanese.
Also looking at resources, I'd say that coastal cities with trade in mind are much more likely and easily placed [dye, fish, whale] whereas desert is harder.
So lets sumup:
- in the short term (game start) the sea is significantly superior
- in the medium term (code of law but no navigation) sea is equal to desert assuming some desert are near you and are settled [getting desert is very luck dependent]
- in the medium-long term [pre-courthouse post-navigation] the sea bonus is much better than desert bonus
- in the long-long term [post courthouse] the sea bonus is exponentially better than the desert one
Misc situations:
- if no desert is around then the sea bonus is astronomically better than the sea bonus
- if the +1 sea trade wonder is built then the sea bonus becomes incredibly better
Finally think of it this way:
Do you find a 2nd harbor in every single city to be more valuable than a 2nd free tradepost in each of your cities.
^-- If the above doesn't convince you then I'd pretty much say you're a lost cause.