Not correct. It totally depends what kind of cycling and running you are doing. If you are rec cyclist that does a couple easy rides a week but you do some brutal run work outs above threshold that will translate into some improvement on the bike. I am not saying this is the way to train but I think you are underestimating the value of running particularly to cyclist that dont know how or like to train hard (eg. my wife). My wife does not like to put in hard efforts on the bike but she plays a lot of soccer, which can equate to a decent run interval workout. Playing soccer allows her to be a faster rider that she would be otherwise.