Horwath has to consider that any potential improvement in Liberal fortunes will come at her expense, since she and Kathleen are virtually identical.As long as Hudak automatically votes against the government, and Horwath can get whatever she wants by playing the 'balance of power' card, why would she change??
The NDP is taking a risk by keeping the Liberals in power and potentially allowing Kathleen to find her own footing.
And I wouldn't read too much into the byelection results. The NDP won Windsor because of the strength of the local candidate, and got lucky that the Liberals made the stupid decision to run Ken Coran in London West.
I don't think either riding demonstrates that what the NDP has been doing at Queen's Park is gaining any traction with voters.