Lions are prolific. The lion was going to die eventually...so...who cares? People have seen too many crummy disney movies.
I confess I didn't dig into the details of this specific case, like, for how old the lion was, etc.
If that one had been a prime male, but past his breeding prime, as in; had possibly been replaced by younger males ---then he would have already been driven from a pride, and would be on his on own.
If so, then his days would be numbered. A few years, at the most. More like six to eighteen months, needing to do all his own hunting, basically alone.
The large males are made for fighting with other lions for territory, and are there to fight anything which would attempt to threaten the pride (pack of females and their offspring).
The male lions lifespans are generally significantly less than the females.
Removing a few males from the population, might not change overall numbers enough to matter.
Whatever one male was doing, there are usually others ready to take his place.
As such, limited trophy hunting, with high tag fees can help pay for game management (if there is honest government around).
You may know all this stuff already.
The people going ape post-banana-consumption over it, watched the Lion King cartoon, too many times?
That does come to mind. (I never watched that one, even once).