I voted no to this, but there are so many variables.
Personally, I know that if I trained heavy 5 days a week, every week, I would get so many chronic or niggling injuries that I would just be doing myself damage and therefore what would be the point of training so hard. And I say this as someone who has trained for around 35 years.
I'm sure there will be people out there who have trained hard for a long time who have somehow avoided injuries who could train that hard.
It also depends what your aims are. If you are a competing bodybuilder then you will need to do what needs to be done, but if not, why risk injury, recovery and possibly not getting the best out of your workouts just to train hard.
I can train 5 days a week occasionally, and do, but if I averaged it out I would probably train 3 and no more than 4 days a week. And that's enough for me.
ps I'd be interested to know the ages of those who voted. I would suspect that many of those who said yes are not over 50!