NotYoda aah that makes more sense 
apologies if I implied that about your comments, however there are those on here - quite a lot who seem to think that, yet it is blatantly not true, excessive speed can clearly be an issue and may even be a contributory issue in an accident, but it is surprisingly rare that it is the only issue...
what is interesting is how many people on here and in life generally really do not understand driving as well as perhaps they should... they pass a test with basic car control and then put in no further effort to improve, they see driving as a means to get from A to B and almost a necessary evil... anyone who might enjoy it is clearly wrong / derranged / bad for society...
yet how many other skills would we do expect the same? music for example, would you really learn the basics on how to make a note on a violin and then do no further practice, have no further lessons, just do the same for twenty years and say that you are good because you have done it for 20 years? of course not, you would have lessons, you would practice scales and pieces, you would look to continually improve... so why don't people do the same with driving? How many people on have had lessons since passing their test? How many practice e.g. gear changes with rev matching for a smoother gear change, or use trail braking to balance a car as they go around a corner - either practising in their normal journeys or actually going out to practise?
and this is evident in the comments - there is a real lack of understanding about driving shown above, e.g. the comments about the poster who does 100mph to pick up bread (IOM so legal!) asking questions about what you would do if the overtaking motobike was coming the other way, and implying there would be a crash! come on, that driver would simply slow down / the motorbike would simply not overtake! Driving at 100 mph doesn't mean getting in the car and going at 100 all the time despite anything else - it means driving in a fluid manner during which the speed might be at 100 some of the time, at other times it might be at 20!
back to the music analogy, driving should be like a well crafted piece of music, slowing down, speeding up, pauses, louds and softs, appropriate always to the context... and like a musician lots of practice is needed to do it well
back to the OP, id a driver simply drives only at 90 without fitting the speed to the context, then that is like a musician playing an entire piece fff and with no expression, the issue is with the driver / musician, not the 90mph / fff which might be okay some of the time...
as for those who say that everyone is laughing at idiots who speed, that would be like musicians laughing at those who are better - it diesn't happen, or they would be the ones to look stupid...
sure, if a driver has only one speed of fast then they are clearly not good, but like a musician, if they have a whole repertoire of options and use them appropriately, and higher speeds are amongst them, but so are lower speeds, they might just be a better driver than you... instead of laughing at them, why not see if you also could improve?
most people get offended if it is suggested that their driving is not in any way amazing, but in reality an hour in a car with most drivers would be enough to suggest changes which would make them safer / more fuel efficient / more sympathetic to the car mechanically - make them better drivers... so why do folks not take that time?