Oh, our plan is to launch poker in the UK!" Um.. ok, and compete with 10000 other companies that had a decade head start and know all about the online poker business. Good luck with that.
I think your reasoning is perfectly logical and yet, it sounds similar to all the VCs who turned down google back in the day because hey all these other guys had been doing search for years so how can you compete with em? You may argue that Google actually had a plan to compete with them to which I'd ask you in how much depth you have researched Zynga's poker plans before reaching the conclusions in your post.
While I don't think the Google Search : Zynga Poker comparison is fair, I think that your comments' parent has a valid point as the online gambling market is pretty saturated. It would be interesting to see if they can do something innovative for the online gambling marketplace.
Probably a long shot, but should online gaming ever come back to the US (and perhaps this will work in other markets), maybe Zynga can position themselves as the choice for casual gambler. If they can convert a bunch of their Farmville, etc users into playing poker, it could make for some very soft games. I don't think you'll see them as the place to be for serious players who want high limits or lots of different tournaments/options, but something that even the most casual of poker players/gamblers can be very lucrative (as well as draw in low/mid limit sharks who want easy cash). This all depends on the premise that the friction from being a player of one Zynga game to being a gambling player on a Zynga game is less than being a player of a Zynga game and also joining an unrelated gambling site.
I think your reasoning is perfectly logical and yet, it sounds similar to all the VCs who turned down google back in the day because hey all these other guys had been doing search for years so how can you compete with em? You may argue that Google actually had a plan to compete with them to which I'd ask you in how much depth you have researched Zynga's poker plans before reaching the conclusions in your post.