Does that seem like a strong argument to you? Of course it's possible to make useless tests. It's possible to be injured by an airbag. It's possible to overdose on a drug that usually saves lives. That doesn't mean any of these things aren't
generally beneficial, or that they should be foregone.
As I said recently on Twitter, I've measured the likely cost of production bugs that were fixed early by static analysis, by leaving log messages to mark where the bug would have occurred. I know that's not the same as regression tests, but if anything it's even more of a long shot, more of a hard sell to my fellow developers, and even in that case the value was strongly positive. About a half million 2005 dollars in that case, for less than a fifth of that in license costs and my own time. The ROI for regression tests is likely to be in the same ballpark.
The fact that something can be done poorly by lazy people is in no way an argument against trying to do it well, or even semi-competently, by people who take their profession seriously.
