So then you admit that you allow your personal biases to influence the assertions you make? I'm not saying that everyone should think that everything sucks, and it's perfectly fine to hope and dream, but when you start making specific claims with the confidence you do and begin to degrade or dismiss the claims of others, personal bias is the last thing you want factoring into your decisions.
As for Garza specifically, he would be alright. Nothing to scream to the high-heavens about, but a solid addition, albeit probably more than a bit overpaid. The thing about Garza is this, though: he has the potential to be really good for the Cubs, or really bad. His BABIP and HR/FB rates have both been right around the average for the last three years, so any fluctuation in those numbers could yield very positive or very negative results, depending on which way he dances about the mean. It might take a little more luck to stay near the average or operate on the better side of it, though, considering he's moving from Tropicana to Wrigley.
If the Cubs were only a few key pieces away from making a legitimate go of things in the NL Central, I'd say open the checkbook and fire away at his agent. They aren't, though, and are likely 3-4 years away from being serious competitors (granted, with astute GMing), and paying Garza a good chunk of money to pitch (good or bad) for a fledgling team for the next few seasons while the pieces fall into place doesn't seem like the brightest idea.