Again, for the most part, folks aren't out there hiking for a living. Which makes the "hiking conferences" more of a hobbyist convention... outside of people that develop products for hiking.
And I'd still recommend those people to hike for enjoyment in their free time and not be out there developing products or trying to sell what their company makes.
If I program for a hobby, who are you to say how I should spend my free time?
Yeah, it would be sad to see someone slaving their life away for their company, but I'm not doing that, and I'm not going to hide that I like to program outside of work (and 100% unrelated to work) because some people on the internet say I should...
And I don't think shaming those who program for a hobby is going to stop companies abusing their workers after-hours...
The 'forest' in this case is that tech companies have been trying to transform work into a lifestyle for 20 years now. And, it has now gotten to the point where one is expected to be 'all in' at one's job or not have a job.
The shirt is cool - I kind of like it. And, coding can be a lot of fun. Both are fine things, in of themselves. But, the problem is the larger context of what's going on: companies are tying to trick people into working more and for less money.
The 'elder wisdom' is that a lot of developers have gotten burned out in this industry over the past 20 years. The best of us have worked hard and long and spilled out our creativity and passion. We have developed successful products that have made some people extremely wealthy. And, yet, we never got our implicitly promised reward.
And I'd still recommend those people to hike for enjoyment in their free time and not be out there developing products or trying to sell what their company makes.