Why do you think the strongest of the strong bacteria are found in hospitals? Because they do a lot of cleaning and disinfecting. The weak are purged, the few who remain don't have to compete with the weak on other axes, thus they can concentrate on developing resistance.
In your home, where you don't clean as strongly and as frequently, there is a wide variety of bacteria who compete against each other, and can't spend too much on developing resistance.
I presume you mean strong against antibiotics and sterilisation. The evolved bacteria are likely weaker along other dimensions (that are less important for survival in a hospital setting). Some evolution is compromises, improving X has cost Y.
Aside: the mega-plate video is an unbelievably good demonstration of bacterial evolution: https://m.youtube.com/watch?v=plVk4NVIUh8 especially note the tree at the end showing how many different mutations evolved.
In contrast, disinfectants might make a bacteria population stronger over time, but as you said, individual weaker bacteria die off (darwinism).
(Edited after 8 minutes to clarify.)