you cant tell if a strain is good or bad buy just growing 1 or 2 seeds , not even from a whole 10 pack ,
you might have to pop 50 or 100 seeds to find 1 keeper pheno of that strain
Thats a bad strain then. Only a noob breeder wouldnt stabilize a strain to that extent. So basically, yes there are bad strains. Sure, if I took the worst strain in the world and popped a 1000 seeds sure, id find a good pheno/geno somewhere. But that still means the strain sux.
A good strain has the following aspects:
Stabilization (2-3 phenos at most. More than that means it wasn't back-crossed properly or wasn't subject to 1-3-1 cubing and the germplasm had to many hybrids)
Vigor (Either f1 hybrid vigor, or stabilized vigor)
Disease Resistivity (not too important sometimes, but if your stock is really susceptible to mold, then it should have been crossed with a mold resistant strain)
Taste, Potency, Feminization Ratio, Germination Rate, etc. are very hard to tell and subject to opinion.
Overlooked strains:
CMH (sensi seeds crazy miss hyde)
Malawi
Some landraces are really great but people shy away from them because they think hybrids are better and some have pretty long flowering times
Bad Strains(i.e. strains that had many many problems early on, stunted growth, multiple phenos where some were very different and worse, susceptible to mold, etc):
DJ Short Cocoa Kush (sounded awesome, but some phenos tasted like ass. literally)
Any doggies nuts seeds, save blueberry. (on principle that $800 is too much for a big bud pheno of the popular strains)
Pineapple Express AUTO (terrible...grew so short that other auto's looked like regular non-ruderalis strains next to it)
Some purple strains just dont grow well. I think it might be that they like lower humidities