It was diluted, call it "pre diluted", in the sense that the political climate of the time, particularly the shrill volume of the tea party, but also including the no cooperation vow the (R) made, would have killed a proposal for a stimulus big enough to largely counter the fall in GDP. So it (bigger) wasn't tried, and so the jobs target was missed. All this assumes that government spending can create jobs, of course.
It doesn't matter that bigger wasn't tried. We were told that amount, if approved, would bring about an employment situation that was no where near where reality came in.
Please show examples of how Republicans cut or diluted spending of projects in the stimulus bill.