The 135mm lens is perfect for kids sports. You can get nice close ups showing their intense focus when they are close and still bring the action to you when they are further off. My 85/90 or 135 are my go-to lenses for this type of use. Especially today zooms with ranges from 24-100, 28-135, etc. show that this telephoto length is still widely sought after in lenses considered to be "walk around" lenses.
I also take issue with 6x4.5 missing the mark. During the film era this was probably the single most use format as it was the darling of wedding photographers. In fact, their use of this format prompted the development of 220 film which of course gave the wedding photographer even more shots (almost 35mm level) before changing film (or most frequently film backs). The fact that it is not as commonly used today has far more to do with the digital push than with any inherent fault in the format. 6x9, though it was extremely popular in the early 1900s, has certainly been out of favor for much longer than 6x4.5.
For me, 110 film and disc cameras missed the mark, but if you look at sales numbers there were an awful lot of cameras sold to those occasional users. Even there you have to identify the "mark" that was aimed at before you can say a product missed.
The Edsel missed. There are probably examples of cameras that missed for one reason or another. But to say a film format or print type missed is difficult to say the least. I think that it is probably fair to say that technology has passed them by, but then that is claimed by many for film in general.