There's no need to be a photographer to collect cameras just like there's no need to be a painter to collect paintings. Collecting stuff might be "useless" because ultimately we cannot bring those cameras with us on the dark side. On the other hand, we cannot bring our pictures with us as well, and they're not necessarily more useful.
Collecting is a basic instinct of man. Some have it more, some have it less. This guy was normal. His wife was insane.
Imagine if Scipione Borghese had to hide his art collection to avoid quarrelling with a nasty wife. Luckily for him, he was a cardinal, so he only had mistresses and, like the lucky gentleman who originated this post, he probably was endowed with excess money that he had to put to some use.