Related: I also love when I can't paste tabular data into Excel/etc. anymore
For the record, I don't hate the idea of stylesheets, but...sheesh
I think it's fairly easy to understand if you understand what it was a backlash against. Tables today are used sensibly, for the most part, but the pre-CSS world was truly absurd in its table use.
The reaction may well have been over-the-top, but it wasn't disproportionate given the state of table usage at the time.
CSS's initial forays into layout seem bad today because people think of tables in terms of their intended use (not the now long-gone monstrosities the community actually extracted from them), but in comparison to the previous ecosystem, floats were a relative godsend.
There were some reasonable concerns. Using tables for both layout and literal tables removes semantic meaning, nested tables can get complicated to layout, and layout the whole page as a giant table makes it difficult to adapt to screen size. But the first could easily be solved by adding a tag that works exactly like table but is for layout, the other two are about overuse of tables in the absence of viable options. We could have easily kept table layouts for the parts where it makes sense and augmented it with something css-like for the parts where it doesn't.
The simple solution:
<table type="layout"> (or "data")