They can, however they are much more likely to be crowded out. The botulism spores are also more heat resistant than pretty much anything else. So the fastest way to die of botulism is canning food wrong.You kill all the bacteria. The botulism spores survive and prosper without any competition. Compare that to failed fermentation for example where you will have a large quantity of a mix of bacteria that is likely to look and smell and taste obviously wrong while not being packed with neuro toxins.