Read:
"This is an important inflection point in our business because it allows us to extract more money out of our customers"
They don't make money from used game sales, resale stores like Gamestop do.
While this is a very questionable move from a consumer standpoint, it makes business sense.
MMOs rightfully charge for multiplayer access, however they have servers to maintain and use the resources acquired to improve their game and keep it fresh.
One could argue that if EA wants to make this idea appealing to customers, they should offer new content for free for the paying subscribers of used games, or those who paid for a new game.
Then again, they may just charge us for cheat codes and "VIP" mode like they have in the past. Even if one were to buy the game new.
Even if the cost of hiring individual programmers has remained constant (and I don't have evidence one way or another there - we'd have to consult something like Game Developers' annual salary survey and apply the appropriate adjustments), development teams have definitely grown in size. Bigger teams mean more developers (from all disciplines), including additional management and QA staff.
There are also other cost areas to consider, such as licensing fees and devkit costs, but I'm afraid that I can't share specific numbers there.
No, they're trying to extract money from people who weren't their customers to begin with.
I would guess that a good number of players who sell their old games use the money to buy new games. This move will definitely push the price of EA's used games down, I would guess by close to $10 for games with significant online content. Which means that EA's primary customers (the people buying the new games) now have $10 less to invest in their new game for every old game that they sell. I can't see people increasing their spend on new games to compensate for this, so the net result could be that EA get more money from used sales, which is more or less balanced out by getting less money from new sales.