That article is a tough one to read, poorly written and very, very colourful!
Anyway... The first thing is that speed isn't the problem but AoA (Angle of Attack). If you aren't familiar with that term you can look it up but basically when it is too high then airflow begins to detach from the wing's upper surface and this leads to what we call "a stall." The airplane doesn't "lose lift" or "fall out of the sky" and it has nothing to do with the engines "stalling" but it's certainly not going to be flying very well when it is stalled, especially at low altitude.
The FAA does not want AoA directly displayed to the pilot so we use speed instead, since there is a loose relationship between speed and AoA, dependent on weight and acceleration, hence all this about "flying too slow."
Your first warning is the triple airspeed displays in the cockpit which are meant to be monitored by the two crewmembers, particularly the PF (Pilot Flying). You can read how this was not done in the Colgan crash.
Next you have the stick shaker, a device that mimics the natural pre-stall buffet present in many aircraft, something familiar to us from our early training in stall recovery, something we get before we even do a solo flight as a student. If you missed the airspeed displays this warns you that your AoA is dangerously high.
Finally you get the stick pusher, which actuates to lower the nose of the aircraft, getting it away from that now too-high AoA. If the pusher comes as a surprise to them then that means the crew have missed the triple airspeed displays and the shaker, when they obviously have a problem carrying out their expected duties there!
Transport aircraft are very carefully designed and tested so that I reject the thrust of the argument that stick shakers and stick pushers are somehow unsafe. They are accepted safety devices but they cannot completely compensate for failure to fly properly; they do not make an airplane uncrashable but leaving them off would make it less safe.