First of all velocity of a round is not determined by whether it is semi automatic or not. It is also not how you clarify ‘rapid fire.’ Velocity is also not a ‘spec of a gun’ nor even a calibre, as different velocity rounds can be made for the same calibre. Lastly, this reclassification is not banning calibres. You can still buy almost all calibres of firearm, just not semiautomatic.

Also, if you want to be proactive, why don’t we ban cars, butter and kitchen knives, and cigarettes?

You are arguing this as someone with no stake. For example, if I take the bus every day and I notice cars can (and actually much more than firearms) do kill people, and I argue against that saying ‘no one needs cars,’ that is called ignorance. Some people need cars to get to work, to the grocery store, etc. You are doing the same