Speed as such is not a problem – it depends how one uses it. It’s common sense, really – if it’s night and empty, I find it terribly annoying for someone to tell me how quickly I shall drive. Drive at speeds you’re comfortable at. Sometimes that’s solidly above the limit, sometimes it’s reserved. And if one wants to kill oneself, one has the bloody right to, as long as no one else is endangered. Also, having to concentrate on the exact speed one is going in order not to get a ticket or looking out for cameras/police cars is hardly safe. Fundamentally it’s not the speeding that’s the problem, but drivers being reckless and unpredictable (not using indicators, driving on the wrong lane depending on your velocity, overtaking the wrong way round etc. annoys the hell out of me). A lack of respect for the laws of physics and the fact that one is trapped in a death-box on wheels is the issue, not that someone strays over the limit.
Also, motorways are meant to be primarily fast, not safe; if anything, I’d lift the limit. If you don’t want to go 250kmh, don’t go to the inner lane. If you don’t have the car or confidence to do speeds like that, don’t. Seems to work for Germany…