Why cannot I pay my WoW from in game gold, at least for some part? EVE has PLEX, which can be traded within the game for pretty achievable amount of in game ISK, and it's a monthly sub game, too.
So why not WoW?
The one thing I can come up with is the fact that the gold spammers would get crazy over this, and Blizzard would be obliged to do something about that problem. For real.
But let's say that the 30 day subscription would cost like 30.000g. It would be achievable by most of the players, but not all (and definitely not by the casual, average Joe/Jane, who is already paying for the much more playing hard core raiders content anyhow). Introduction of this kind of 'trade goods' might even spice the AH up because everyone would know that the money could be of real use to you.
In EVE, as far as I understand, it's possible to play for free by 'grinding' enough ISK to stay on PLEX all the time. Still only part of the population is doing so, as can be seen from the fact that CPP Games, EVE's Blizzard, is alive and kicking, and obviously not doing badly.
Granted, PLEX is a player purchased thing, which they sell in game. This means that someone has to pay for the PLEX to begin with, so people are in a way selling their game cards for the money to sustain their extraordinary crafting costs for their extremely expensive ships or stations. There are no such money sinks in WoW, and I'd say that all gear and enchants are very readily available to everyone who wants to have them.
Damn it. I just answered my own question. WoW can't have a in game purchaseable subscription option, because there is no real money sink to put the in game money to.
Can it be so simple? What do you think?