I assume that for most humans it is easier to see the "finding bit X" problem as one of dealing with strings, than as one of calculating (although, of course, the latter is much easier for the computer).

In other words:

sprintf '%b' converts to a string of bits, then I can take the 7th char from the right

is easier to understand (for most humans) than

If I have it as a number, I simply "AND" it with 2⁶

Of course, it all depends: if there are millions of lines, the inefficiency will add up and become noticeable.