I've found most of the older books work on tables. I suspect this is because the tables are generated via empirical testing, rather than mathematical models. Today we have the ability to analyze materials and components, quantify their properties, and make mathematical models which we can input these values to generate a "right" answer.
For the true propeller heads with a math or pile it higher 'n deeper degree, this is ideal. For the majority we just want a table derived from inputting these values, and that's how it's been for a long time. Unfortunately I think there are a couple of reasons for not publshing tables anymore, pedantics and liability.
The pedants who publish the books say "gee, but that's not precise, they should know how to calculate this..." and the lawyers say "well, if we publish tables based on assumptions made about materials, we could be liable if some nitwit hurts himself or others".
They can't be certain of the intelligence of who is using their data, so they just default to "here's the facts" mode and ignore the useful information.
Fact is, if someone uses an inappropriately small "something" where a bigger "something" really should be used, they screwed up. Chances are they'd still mess it up even with the properties data. At least with a table, they can learn "gee, maybe this ain't right".
MHB clearly states their tables, where not absolute, are [conservative] starting points for the reader. That sounds like a perfectly useful CYA for me.