Personally, I think the current balance of income from prize pools vs sponsorship actually makes for more interesting competition. Playing to win is much more important than playing to stand out right now, and I feel like it makes the game more pure.
I find the idea that players should feel some sort of obligation to alter their strategy for the sake of appeasing fans to be pretty bizarre. I feel like there is a correlation between where you stand on this issue and where you fall on the Alliance - Navi spectrum of fandom.
Regarding the finals specifically, why would VG choose to prolong a game they have very little chance of winning when it becomes increasingly harmful to their psyches? Sometimes it is a relief when the team I'm supporting GGs early in the game knowing that it would have probably destroyed their confidence if they had spent another 40 minutes being pushed around in the vain hope that they might be able to somehow pull off a surprise victory. 20-5 at 20:00 minutes and 47 - 7 at 60:00 is still 1 point for the victor, but a 60 minute stomp takes a lot more out of the losing squad.
Even the very last game in the series, I can't blame VG for not fighting until the ancient fell. They have so much emotionally invested in the outcome. You can see it in the player interviews. I would feel pretty weird insisting that they should have to prolong their defeat and deal with that state of being for an additional 30-40 minutes for my amusement. The final series wasn't fun to watch, but sometimes in life things don't turn out the way you hope. In entertainment, you alter things to make the boring things more exciting. TI3 isn't going to happen every year, but when it does you know that the players aren't thinking about their fans or their sponsors, they're thinking only about winning.