Ever since consumers started expecting metal objects to stay "shiny" even if never dried or oiled or even cleaned, manufacturers have shifted from carbon steel to stainless steel. You might as well call most stainless steel "edgeless steel".
"Carbon steel" rusts easily but is hard and can hold an edge. It is fairly easy to heat treat it WELL so that the edges come out hard but not terribly brittle.
Affordable stainless steel is harder to heat-treat at all, and almost impossible to heat-treat so well that the edge comes out hard. As a result, most stainless steel tools are made cheaply and given a fairly cheap, generic heat treatment that leaves the edges anywhere between soft and very soft.
It's hard to put a good edge on soft steel, and using a soft edge turns it right into a dull edge.
There are a few very expensive stainless alloys, like 440C and molybdenum-vanadium alloys. The metal is expensive and the heat-treating is slow and fussy and expensive - but if you put enough money and effort into it, you CAN get very, good hard, stainless edges. Surgical scalpels are one example.
For consumer items like pruning shears, most manufacturers decide to make their money from undiscriminating consumers and those who will never come back with any return business. They target the MASS audience of people who will always buy the cheapest item they can find, and then complain about the quality.
Apparently most people fall into that category, because the parking lot in front of Wal-Mart is HUGE.
Here's a trick question: "How big are the parking lots in front of stores that only sell high-quality products even though they cost more?"
It's a trick question because there aren't any stores like that any more. Customers fled the prices, and never came back for the quality.
That's why we keep building more Wal-Marts, importing cheap trash, and putting skilled workers into unemployment lines.
The next step will be pruners with plastic blades. Plastic is even cheaper than stainless, and manufacturers are bound to explore the outermost limits of "HOW cheap can we make it before they stop buying trash?"
