I think we hear it all the time and immediately go to dif reasons much further down the chain like ie. blamed genetics assumed poor germination practices yada yada yada
I know for sure i have been sent seeds in the past that i only treated half of them and the entire batch that was treated germed and survived and the ones that i didn't treat because i ran out of h2o2 at the time and every seed in the batch was fungus propigated
point is it hasn't been the only time and as a matter of fact that example happened rather recently from a very well known breeder
between the two the only change in variables was the treatment
they were veged in the same container in this example it was the only variable aside of other contamination like the seeds being contaminated from a fungus and then stored
either way if one properly eliminates contaminates from the seeds before planting non of the above matters really

but rarely do i hear of people properly decontaminating seeds before planting I would NEVER just throw a bean that was given to me into the room w/o sterile precautions before hand
but hey that just my 2 cents
not saing my way is the best just the way i do it