We recently got a paper accepted at a conference cooperating with our local university and my employer was more than happy to pay for that time.
What's the real problem IMO is that studying, training, etc. is pushed to your time off. When you account for all of that, my 40-hour week is more like 50 hours.
I think people very seldomly took him up on the offer and if they did, I would guess there was a certain probability that he would read it as a negative signal along the lines of: This person is really going out of their way to do networking, so they're probably working on finding their next gig so they can leave the company.
In one other company I worked at, the company was keen on conference participation, but the way it would work there, if you were the person doing the legwork it would be your boss presenting at the conference. So you couldn't really use it as an opportunity to make a name for yourself. You'd just make a name for your boss.
I've also done extensive freelancing. If you run a low-risk freelancing strategy, clients pretty much expect you to work for them fulltime. It's already a tough sale to get them to give you a day off every quarter to do your own bookkeeping. And the hourly rates aren't high enough to allow you to spend several weeks or months in between freelancing gigs to work on status-building. ...now if you're using your status-building to get the most choice consulting opportunities where you have the bargaining power to do few hours at high rates that's a different story, but that's a different kind of freelancing altogether. (The "high-risk" kind which I'd distinguish from the low-risk kind that my personal experience is limited to).
If you lose interest, there's nothing wrong with pursuing a different career -- I know a couple of people who started over because they just couldn't bear how boring tech jobs get after 20 years.
I guess other professions have similar things going: Lawyers might take on high-profile cases on a pro-bono basis to build a name for themseves, or contribute to academic publishing even when they are not on payroll in any academic capacity, etc. But they have a different culture to go with that. As a lawyer, I guess your X-hours work week will stay an X-hours work week and your non-billable hours Y are simply subtracted from X.
But most jobs in the software engineering profession come with the expectation that you have an X-hours work week, and your employer usually does not allow you to use any of that time for personal professional status-building through open source or publishing etc. ...your only chance is to do it on weekends, which eats into your work-life balance.