If I didn't waste my time and money on photography then I'd waste it on something else
Most of the best (or at least, best-known) photos ever taken involve people and I just don't have the bottle to wave my camera around in front of strangers on a regular basis so I know I'm never going to make it 'big time' in photography. I therefore retreat to subjects that don't answer back!
One thing I like to do is to 'de-mystify' photography to help others realise what can be done (i.e. if I can do it, anybody can!).
From a personal point of view, a picture can be worth a thousand words and not being a very good note-taker or diary-writer, I find a photo really does give me a record of a previous event which might well have been forgotten, otherwise.
As an example, when I was a lad at secondary school in the early sixties train-spotting was
the thing to get into (this may seem strange to younger generations nowadays, but in those days it was a great way to get out and about and broaden your horizons, etc., etc.,). This was an interesting time on the country's railways with the changeover from steam to modern traction but, crucially from our point of view, none of us in my circle of friends had a camera suitable for recording the contemporary scene so we can't look back on that time other than through our fading memories!
When my own son took an interest in railways as a much younger lad in the early nineties I made sure that I photographed everything possible, knowing that he'd find that railways were not 'cool' when he got to the age where we first started! As a result, not only do I have a great reminder of a time when father and son could share an interest, I've also got a first-class record of the railway scene of the time which has already changed quite considerably within the last decade or so (whether the photos will ever have any commercial value is another matter altogether, though!).
My wildlife photos also bring back memories of days out with my mates both locally and to far-flung corners of the country. More recently I've taken the opportunity to record some of my local wildlife in closer detail and hopefully, this will be of some interest at some time or other though, again, whether it has any commercial value is open to doubt!