Why doesn't this anonymous function work with `rowfun`

?

```
>> T = table([43;52;67;28],[64;24;69;45])
>> rowfun(@(x) sum(x), T)
Error using tabular/rowfun>dfltErrHandler (line 497)
Applying the function '@(x)sum(x)' to the 1st row of A generated the following
error:
Too many input arguments.
```