Author of minify here. In general a lack of newlines does not mean it is minified well! You will actually see that other minifiers would use a space instead of a newline, which results in the same file size. Whitespace (space or newline) is significant between phrasing elements (such as the A tag), so these space must be preserved in the same way we preserve spaces between words.
Other insignificant whitespace is always removed (unless you use display:block on an inline element and then depend on whitespace for element positioning … BAD!).
If you think a space could be removed safely or a whitespace is removed that is unsafe, please report a bug at the minify github!