I understand that certain displacement categories are popular due to their connection with racing and other traditions, but given that larger displacement does not necessarily mean a proportional or even consequential increase in engine size and weight any more, I don’t see the point in certain classes of street bikes, in fact it seems counterproductive that so many street bikes adhere to racing displacement categories and parameters.
In particular why not simply increase the cc’s of some of the smaller to mid size bikes (such as the 400’s to 600’s) and de-tune them proportionately? You would have a torquier, less high strung, wider power band, more tractable engine with no real detriment in terms of weight and size. You might even have an increase in reliability due to lower stressed components.
Even in the high tech high rev race replica street world perhaps the tradition of “there is no replacement for displacement” still has merit, as long as it’s not taken to extremes, such as with cruisers and the dogma outdated Harley design.