Directly proportional? No.
But obviously the numbers of games (and their percieved quality plus attractiveness for different demographics) does play an important part in demand for a console - games after all are a key reason to buy one at all.
What matters most I'd say is the spread of attractiveness of the games/services on any given console and I think your own charts point to that - plus previous consoles/games performance as well.
Consider say Halo 2 on Xbox - sold hugely yet Xbox itself didn't. This is because the demographic appeal of the Xbox (and by association the spread of attractiveness of its games/services) was actually fairly narrow vs the PS2 which I'd argue had the best spread of attractiveness ever for a home console - with obvious results.
This gen the Wii for quite a while managed something similar - it appealed more overall to more people. But then it's key appeal factors stagnated.
Meanwhile the 360/PS3 really have been kissing cousins practically the whole time - with games/services which have appealed fairly broadly but hampered by region which has curtailed their success to almost identical levels.
Try to be reasonable... its easier than you think...
