Except that it makes predictions, and many (ie all that have been tested) of these predictions have been shown to be true.
For example
The intermediate forms between (other) apes and people, if they are preserved as fossils at all, will be found in Africa. (Darwin)
There were intermediates between terrestial mammals and cetacians (whales, dolphins, etc), and also betweeen land mammals and syreniae (manatees, dugongs, etc).(Darwin)
If a pseudogene, transposon, etc, is found in the genome of people and orangutangs, it is also in chimps and gorillas.
If a pseudogene, etc, is found in cows and whales, it is also in hippos.
Ditto for cats, dogs and bears
No fossil elephant will ever be found in Hawaii
No fossil mammal will ever be found in Cambrian rocks
Precambrian life existed (Darwin)
No fossil intermediate between birds and mammals will ever be found.
And many many more...
All of these predictions are true. Pretty good for a "feeble theory", heh?