This type of article is interesting, indeed, but not for the reasons you think.
It includes well known facts to give some credence to the text, but then introduces faulty reasoning and carefully selected and presented, but frankly biased, data.
For example, it says that the bacteria are only dangerous in the presence of dirt (okeish as unclean wounds are mostly to blame), but it still remains that dirt without the bacteria can't cause tetanus.
As with many infectious diseases, measures other than vaccines have also worked to reduce incidence and mortality. But vaccines remain important to be able to bridge the gap between low incidence and virtually zero incidence.
As with many diseases, there is a dose-effect relationship. Adults are likely to have come into contact with the bacteria itself and probably low dosages of the toxin. However, most of us in clean environments haven't and there's a risk that people in more remote regions can't get some wounds properly cleaned.
The risk-benefit analysis on this one says that the risk may be low in terms of likelihood, but the effect is too serious. So, while most people will be OK without the vaccine, if you do contract tetanus, it could easily kill you or leave you seriously damaged.
It's the same reasoning as for seat belts, for example.
Current vaccines are safe to give. And single shots for multiple illnesses do reduce the likelihood of complications from the inoculation itself.
No problems with the number of illnesses as our bodies are used to coping with several different potential pathogens at the same time.