The most often-quoted study about UTIs and circumcision IS, in fact, a load of hogwash! Published by Thomas Wiswell, the study found intact boys 10 times more likely to have a UTI than circ'ed boys.
But actually reading the study reveals that most of the intact boys were not circ'ed because they were premature, or otherwise too sickly to tolerate the operation. Many of these babies were hospitalized; many had catheters. It is hardly surprising that these babies had relatively high rates of UTIs.
But this group was compared to healthy, full-term, circumcised babies who were sent home right away. Anyone who has even casually studied statistics realizes that these two groups are NOT equivalent.
The most reliable studies looking at UTIs and circ status suggest a slightly higher incidence of UTI in intact boys in the first year of life; after that, circ'ed males are slightly more likely to get them. Circumcision does NOT prevent UTIs.
And the bottom line is that UTIs are not very common in ANY boys. Girls are much more likely to get UTIs than boys. When they do, they are generally treated with antibiotics. Circ'ed boys with UTIs are treated with antibiotics. There is no reason why intact boys cannot receive exactly the same treatment, should they get a UTI.
You're absolutely right - it makes NO sense to circumcise a healthy baby (and introduce a host of surgical risks) to possibly slightly reduce the risk of UTI. That's why NO medical organization in the world recommends routine infant circumcision for medical reason.