IMO too many of the C&V members have not looked at bike frames from way back. Older frames from the 1890 to 1914 period that I have seen photos of frequently sloped, some even sloping the reverse direction from what is now common. Yes there was a period when the vast majority of sporting bikes had flat top tubes but most American cruisers did not and neither did Mixtes or other designs for women in skirts. You are defining the "right" look as being the look for a medium size steel men's road bike from the period between about 1920 and 1990.

Sloping top tubes allow better engineering of extreme sizes of bikes in a given wheel size per my understanding with less compromise in BB height and top tube effective length. I have seen some 1970s era small frames with compromised top tube shapes to allow for front wheel clearance.

I like the looks of the VO Mixte and note that it is available in up to a 58cm size, something hard to find in older mixtes. Also note that it is lugged construction, at least according to the VO web site. Does the sloping "Top Tube" bug the so called purists? How about the top tube on a Schwinn cruiser from the 1930s onwards.