Define 'economic stimulus'. Do you mean it will stimulate the private sector to start spending more autonomously? Or do you just mean any additional money spent anywhere by anyone represents a stimulus?
If the former, I'm sort of a believer in 'you can lead a horse to water...'. An economist I work with recently demonstrated that the last 10 economic stimulus packages implemented by the Japanese government had zero positive effect on the real economy. I'm guessing it's simply because the private sector sees that money is being spent, but because the economy is still clearly in recession, they don't want to commit their own money to it yet. They know that the govt. is spending this money because it (thinks it) has to, not because it has any faith in the strength of the economy. So why should they be convinced? Since things in Japan failed to get better despite all the govt. money, the conclusion is that they actually got worse due to the stimulus. If you get the same counter-intuitive results 10 times in a row, you have to start looking around for some sort of explanation for it, no matter how counter-intuitive.
If it's the latter, then yes, obviously the position as you interpret it is nonsense. The govt. spends money, there should be a stimulative effect from that alone, ignoring sentiment.