There was an AMA on reddit a couple months ago from a former Zynga employee. It gives a look at life inside Zynga (obviously from a semi-disguntled Zynga employee point of view)

Notable quotes:

But the teams weren't left alone to make the final adjustments. Someone up top would always feel like they knew what had to be done. So some major (and often uninformed) changes were pushed on the team and they would be forced to change features that would ultimately disrupt the rest of the game and cause the entire project to fail.

Their major issues are the inability to adjust to the changing market. They did great when Facebook gaming was on the rise, but now it's declining and Mobile is on the rise. They're trying to change over, but employ too many of the same game development "best practices" that were developed for Facebook games. These just don't translate to the mobile market, which is why they're suffering in that market.

There's also lots of other issues internally. A lot of micro-management from the top down that stifles the creativity and hinders the production of many games.

An over reliance on every game being a blockbuster hit which makes the fun aspect of games suffer while making the money grabbing tactics all too transparent to the users.

And a serious lack of foresight over all. Too many major decisions are quick reactions to sudden changes in the market. If some games jumps to the top of the Top Grossing charts then everyone need to drop everything and change to follow it. Which wastes time, makes for bad design and ultimately puts projects behind schedule. It just means they're always late to the party, and whatever game they're trying to compete with has already faded away by the time their own version hits the market.

They rely too much on reacting to what is making money now, and too much on their own data. They don't strive to make anything new or innovative and that's no way to excel in the games market. You need to lead the pack, not try emulate the best practices of top games with the hopes that you can out perform and already established IP.

On ripping off other games:

After The Ville got sued by EA it was much less okay to "fast follow" a game (The term for copying a game). I think that early on it was blatant. Later it became well known practice at Zynga, but rather poor taste. Dream Heights/Tiny Tower was a big slap in the face. Sims Social/The Ville was the last straw. Towards the end of my time it was not so much that games were straight up ripped off, but key features would be. Such as the general method or menu flow that a game handles it's multiplayer. The idea being that if it works for that game, it would work for our game.