Yep. Of all the stupidiness, that might very well be the most idiotic design decision they made. It makes absolutely no sense to penalize the player for building roads in a 1upt game.
Road costs would actually add some tactics to a game like Civ IV, where you would have the option to slow down the opponent by placing good defensive on the road, to block the enemy SoD to reach the main attack force. You'd be forced to build the roads in smart places, and you would have to decide if you were willing to take the risk of only having one road.
However, in Civ V, since only one unit can use occupy the tile, you can't really block the road in an effective way, and even if you could, it would only affect a couple of units, since most of the units are going to walk beside the road.
It's so stupid that I still can't believe that this made it past the beta testing. The stupidiness of this is not my opinion, it's a freakin' fact. I can't imagine that even the most hardcore fans of this game could defend this design decision. It's like the developers were brainstorming and wrote down 100 ideas, mixed them all in bag, without even discussing how they would affect each other.
The more I think of it, the more stupid it seems:
Ok, I get the problem. The SoD's got incredibly large and people would get pissed when Monty conquered your pretty civilization with 40 knights and you really had no chance to stop him.
The easy solution would of course be to make armies more expensive, increase war weariness, make city walls and such more powerful, turning other AI's against the aggressive civilization and so on.
What did they do? Quite the opposite of what you would expect. Instead of making armies more expensive, they reduced the tile yields which affect everything else in the game as well. They decided to completely remove war weariness, so you can now fight an eternal war without any consequenses, (except for accidently capturing cities that is). Even though the cities can defend themselves, you can no longer stack 20 units behind your city walls and hope for the best. And the AI will always hate you, so it doesn't really matter if you try to play nice.
When you think of it... they decided to go with 1upt to remove the SoD's... And in order to make it playable, they had to reduce the number of units, by lowering the tile yields. But wasn't the entire problem with the SoD's that there were to many units? Do you see I mean? They want to decrease the number of units in the game, and somebody shouts "Hey, let's add the 1upt rule! That will fix it for sure!". But in order to implement, they must find other ways to reduce the number of units. So basically, they could have skipped the 1upt rule and just decreased the production values, and the SoD's would have been gone anyway. So what was the purpose? Probably to turn Civ into a board-game-like tactical war game ala Panzer General.
Fans of this game will often claim that I "just want Civ 4.5" or something like that, but I actually really wanted a new, different Civ game. I actually like the idea with hexes and 1upt before I tried the actual game and if it was implemented in another way, I might actually enjoy it. But the problem is that nothing seems to fit together.
Lower tile yields and limited resources would be more than enough to stop the SoD. If they still thought it would be a problem, they could give all units the ability to cause collateral damage. This could actually lead to some interesting tactical decisions. Should I send of my units out to block the enemy road, or should I keep it in the stack? But no, instead of giving the player the option to make tactical decisions, they force you to do it.
This leads me to another stupid thing: The removal of transport ships. Sure, it was not fun to transport that SoD with 40 units across the world and then sit there with 10 empty transport ships with nothing to do. But since the SoD's are gone, you would now only need a couple of ships. So again, the purpose of adding the embarkment feature, is clearly to make it easier to move your army between different islands. But since you have so few units to worry about, this wouldn't have been a problem anymore. Would it be such a problem to build a single transport ship? Heck, you could even give military ships the ability to transport units if you wanted to streamline it that badly.
So I guess the bottom line is: Nothing makes sense.
