If you want to call this a 'worst' grinder, OK.
But, I'd call it the 'saftey' grinder.
It won't grab parts and fling them at you (at least very fast/hard), if it does bite your finger - it's more like a nibble (no loss of blood/flesh), and if it does remove metal (hardly ever a problem) it removes so little there's little danger of harming the part.
I present Li'l Red. My Dad gave my brother and I, each one of these, as a Christmas present over 40 years ago.
After reading about CM Block Motor Grinders on-line, I saw the 'light' and bought my 1st Block grinder. Life hasn't been the same or as safe in the shop since.
Maybe you've seen my posts on a 1 H.P. Block Grinder Model 257.191600 restore -
Go-Blue! .
I filled in the dent, repainted, and applied the label since the above pic. was taken.