There's nothing wrong with enjoying lore from old products. That's why most of us keep all our old books and material, so we can read it and draw from it when we want. And nowadays we can even buy more of that old material as we feel we need it or want it from DMs Guild, Amazon, your Friendly Neighborhood Game Store, etc.
But to think we need that lore material re-printed more or less as-is in a new format for a new edition is just not necessary if you ask me. (General) you already own the material. Why do you need it re-packaged in a book that has the current D&D logo on it?
I mean I have to assume it's because (general) you just don't want to put in the work to translate the old material's mechanics to 5E and have it all together in one shiny book. But there's no requirement that WotC has to make (general) your life easier for you by doing that. They're writing books for the general populace, not you specifically. So while I can certainly understand the desire for a pretty 5E book that re-prints the old lore as it's always been (with just mechanical updates)... I also understand why WotC wouldn't have a desire to do so. After all... that'd be like them deciding to re-print the 5E14 PHB, DMG, and MM for the 50th Anniversary just with new cover, new art and the pages re-organized a bit, without actually updating rules that everyone has been saying have not worked for the last 10 years. While I'm sure some people would be perfectly happy having just having that... more people than that would wonder what exactly would be the point.