You do not want to split CIO in half and make Australia further away from Africa. Conflict should be encouraged rather than discouraged. When designing a map of any kind, sea lanes or not, conflict is key. We want maximum conflict in as many areas as possible. Insulating Australia is not a wise decision.
And reasons for reducing the number of lanes have been given, too many make for increasingly difficult defense as has also been pointed out. Defense may very well have been too easy to establish in the standard game, sea lanes were introduced as a way to lessen that defense. Great! But it seems this idea went too far in some areas. That's not to say the sea lanes are a failure, far from it, I can see how they can help in many ways in many areas, but more is not always better and defense is not a bad word in this game, to ignore defense and yes, even stalemate lines is a bad idea as well! Stalemate lines should not be simple to set up but they should not be nearly impossible either, with 4 sea lanes per Ocean space, we have taken that step too far. If (as some argue) they work just fine, then why not add another 3 or 4 sea lanes to spaces, make some Ocean spaces contain 10 lanes!? Obviously we get to a point where we have too many, 4 seems to be that point and it is playing out rather poorly in the first game in the Indian Ocean. To the "casual observer" it looks pretty intense and fun, yet it is not working too well for those involved and has even caused the game to shift to a too heavy fleet game at that and as such is affecting all aspects of the game in odd ways. (for example, alliances are much tighter now because they are forced to be so, Land wars are less intense than they used to be as well, everyone is too focused on the oceans as things now stand) Reign it in a tad. Yes, apply the lanes evenly throughout, this means adding lanes in some areas but it also requires dropping them back in others as well for a much more well balanced approach.