> Psychologists call this black or white thinking

The same can be told for your thinking. You (and several other posters) lumped several arguments into the same Nirvana fallacy [1]:

1. It's not 100% effective

2. It's only 50% effective

3. It is not even 10% effective

These are very different from each other. The first one may actually mean what you described (either something works perfectly or it's useless) but the others must be discussed separately.

[1] https://en.wikipedia.org/wiki/Nirvana_fallacy