Food boards are the best way of discussing food, I think we will see a return of their influence when enough people finally rumble the bloggers' game.
I totally agree and share your hope, food boards are for discussion, food blogs are for self expression - I've never seen on a food blog a meaningful discussion of the type one can have here on eg, just sequences of more or less inane comments.
You also mention earning money. I don't think anybody who's wealthy enough to go frequently to very good restaurants anyway will find it easy to make a serious change to his income through blogging. There are, it's true, some pathetic souls who move mountains to announce themselves to PR companies in search of a free meal, but they must be either desperately poor or have lacked affection as children. And it is doubly pathetic that restaurants waste food and money on them.
'Status building' may be as you say another possibility, but once again real status is obtained by a minuscule fraction of food bloggers, who most often, like the Dos Hermanos case mentioned by Harters, are professionally interested in food related careers. Apart from them, I guess well-adjusted people try to gain status with their peers in their own profession and don't consider fooblogging as a means to gain status.