this is not my experience at all - if they are the correct length the shimano style link cables actually work very well - they really help reduce the amount of slack by setting up better angles in my (admittedly limited) experience in addition to removing the risk of the straddle cable becoming stuck in the tyre if the main cable breaks
I've got the shorter ones (73mm?) and they are pretty much the perfect length on low profile canti arms if the brake block posts are set up so that the blocks hit the rim parallel - I wouldn't want the straddle disk any lower