When did that trend of blame game start happening?

It would be the fault of publisher if they failed to market the game.

It would be the fault of the devs if they failed to make the game appealing.

It's only the consumers' fault if they keep on buying bad games. It's not their fault neither if they don't know about a good game that exist because publishers failed to market the game properly.

its never the consumers fault with expection to priacy. 

If the game was great but failed to sell it could be that the game didn't have an big enough market or that no one knew about it. Or the game was crap and so the dev should of made an better game. 

Its never the consumers fault.

You completely missed the question, LOL.

When did it start happening that the consumers got blamed?

Technically it's always the consumer's fault a game didn't succeed in sales. If they don't buy it, then it doesn't make money. This isn't a 'start happening', it always is. What started happening is developers and publishers started moaning about it even after spending thousands on advertising campaigns and millions on development.

In previous generations games were cheaper to produce so required less sails to make money.

... is that a good answer to the question?

It's always been happening, the difference is that we hear about it more now with things like the internet. It's like when people say 'Back in my day, there was less crime', which is complete bullshit, it's just that back in their day the world was so small to them and only reached to the edge of their town or state. Gaming journalism has also grown over the years, ten years ago it would have just been made of 10 major magazines and then maybe 10 smaller magazines, these days we have hundreds of game related sites, forums, social networks and video channels. That means that publishers and developers have far more outlets to give out their opinion on things and they have way more journalist hunting them down for answers.

Very simple, when the budgets and the ego of developers inflated... that's when blaming the consumer started.

I think he did answer your question.

my bad, i can see i totally missed the question. 

Pretty much this. Attitudes remain the same, but access to attitudes that normally wouldn't be aired (since blaming the consumer is, you know, bad) get aired because devs and publishers have (as all people do) loose lips, and these inflammatory opinions are aired TMZ-style for the gaming public to consume for their own brief amusement.