S-pedelecs, and e-bikes are a new development and so fall between the cracks. Riding them on the bike paths may endanger other cyclists, riding them on the main roads endangers the users of the s-pedelecs and e-bikes. There isn't really a 'third class' and legislators all over are struggling with this classification problem.
Tieing in s-pedelecs with pedalling rather than with throttle based systems is a legal hack, but in practice the hack works quite well. The only situation where it doesn't is when you ride an s-pedelec in city traffic where you are forced to ride between the cars, who get irritated because you are measurably slower than they are. Plenty of towns are re-considering this now and are making explicit allowance for s-pedelecs to use the bike paths. But there are already so many 45kph scooters that break the law that the difference is likely negligible.
If we classify stuff together and then ask what legislation we want to enact it’s clearly backwards.
This is why in UK law at least classifications are generally tied into specific bits of legislation (ie definitions).
If both are the same safety, why make one illegal? It seems like a law which restricts liberty for no reason (other than legislative convenience, or because 'the government decided to tie it in with pedalling because they decided to').
It seems like the argument is 'bikes with pedals which can be powered with a button can never be classified as bikes because existing laws say that they are not classified as bikes'.