My first slr standard lens was the 57/1.4 Konica Hexanon. Even though many years have passed since then and I have a number of systems, a 50 still seems a little wide to me. Canon's manual focus SLRs have a relatively short film to flange distance and Canon started with a 50mm standard lens from the beginning. If you include macro lenses in the normal range then the longest obvious ones were the 60mm Leica SLR and Zeiss (Yashica/Contax) models. I also had my father's Konica Auto S1.6 with the 45mm lens. I have a number of 40/1.8 Konica Hexanons and I like them. Why did Konica supply this a a kit lens? I don't think it was to show off their lens designing abilities. Camera companies were still in the mood to downsize cameras and lenses. Most people date this to the 1972 Olympus M-1 (later OM-1). I date it to the introduction of the Fujica ST-701.
Apart from my fixed lens rangefinder cameras with their shorter-than-50 lenses I have other short ones. These include two different 45/2.8 GN Nikkors, the already mentioned 40/1.8 Hexanons and a 45/2 Rokkor. These lenses might be a little more popular but there are many zoom lenses which cover these focal lengths. The zooms don't always render lines as straight as a prime lens so they aren't as suitable for architectural work. The change from 6 element f/1.4 standard lenses to 7 element models took a while and not all companies made the change at the same time. The Canon 50/1.4 FL II is from 1968. Konica did not go from the six element 57/1.4 to the seven element 50/1.4 until 1973. If my timeline is right Minolta went from the six element 58/1.4 to the seven element 501.4 in 1973. The older six element designs are usually technically not as good but sometimes have more pleasing out of focus rendition. This is also true of the comparison between the older 58/1.2 Rokkor and the newer 50/1.2. Illumination over the whole area of the format was usually also better with the newer design. When it comes to standard lenses slower than f/1.4 the older design could still be excellent, with improvements coming mostly in coatings.
For me, a lens in the 40-45 range is not quite as attractive as a 35 but if it's smaller and lighter than a lens in the 50-60 range it can be nice to use outside and in good light.