What does it take for a Company to leave the console business?

[Final-Fan]

for the OP question:  

As long as consoles make a profit the company will stay in the business; the Neo-Geo lasted a very long time despite the miniscule market share because it was never a losing proposition.  

Companies can bull through a period of unprofitability if they believe that they can get back into the black.  How much they can go into the red before drowning is a question of deep pockets and determination.  

Nintendo has very deep pockets due to massive cash reserves and 100% determination due to being ONLY a video game company.  They also have a knack for being profitable even at low market share.  People, Nintendo is not going anywhere.

Microsoft has extremely deep pockets due to Windows and massive cash reserves.  Their level of determination is harder to guess, but it has to be pretty high since they have proven their willingness to go several billion dollars into the hole.  I would say that Microsoft could be convinced to leave the industry if faced with another generation of small market share and massive losses, or two generations of losses.  

Sony usually has very deep pockets due to being a giant electronics company, with bonus points for manufacturing ablility.  But when the main company is not very profitable then they are not as able to fund the video game wing.  Sony's determination has been high but due to recent personnel changes it is unknown whether this is still true.  Also unknown is Sony's ability to remain profitable at low market share.  I would say that Sony could be convinced to leave the industry if faced with one generation of massive losses, or two generations of losses.  The fate of the handhelds would probably not be tied to that of the consoles, and vice versa.  Sony is probably the least able of the three to resist periods of hardship.