But firms don't try to maximise short term profits

It's a standard enough trope, that modern capitalism fails because companies only ever try to maximise short term profits. Not enough is done to think of the long term. Yet there's a simple enough point that can be made about this. Any firm at all that invests in anything cannot be said to be maximising short term profits, as David Henderson points out:

He said matter-of-factly, as if there were no doubt, that profit-maximing companies maximize short-run profits at the expense of the long run. "If that were true," I replied, "then drug companies should end all R&D today. Their R&D expenses would fall and their profits would rise. And yet we don't see them doing that. They invest hundreds of millions of dollars in drugs that, in many cases, will not bring good earnings to them for a few years and maybe for 10 or more years."

Any investment in anything more long run than refilling the ink jet printers is evidence that a company is not trying to maximise short term profits.

Now, it's possible to think that perhaps companies should pay more attention to the very long term, this is true, but then we come to a rather different problem. Which is that companies are already the most long term looking organisations around. Governments, famously, never look beyond the next election day, we as individuals are known (indeed, it's often used as the proof needed that governments should nudge our behaviour) to suffer from hyperbolic discounting, paying insufficient attention to the far future. Which really rather leaves only companies as the organisations that do try to look out beyong 5 or 10 years. The major oil companies, for example, are famed for having 30 and 40 year horizons. And there's just no one else in our society that is looking that far ahead.