Of course, as a 40 year old Libertarian, I may be a bit biased.
Even IF the use of that force would be to prevent me from making a bad choice, it's still wrong. Outside of economic arguments which are largely rooted in the Austrian School, that is the mindset that defines Libertarianism.
Now, as it happens, I will argue that, in many, many case, I do "know better", regarding things that pertain spefically to me. And that may be a bit of conceit, and that conceit is probably common to many Libertarians and is probably the essence of your statement above. But I would be a Libertarian whether or not that was the case.
1. Some prominent people are libertarians, and outspoken about it (Peter Thiel, Jeff Bezos, Eric Raymond, etc.), so the ideas are circulating in the community.
2. This part of the economy is doing well, and as a result techies have little personal incentive to support any alternatives to free-marketeering. We generally have options and can get away with telling our employers where to stick it, if we don't like their policies, without the result being poverty. Being in an "employees' market" where we have substantial leverage insulates us from many of the less enjoyable aspects of market economics. In a few situations where this doesn't hold, e.g. the issue around health insurance for small startups in the U.S., I think you do see considerable defection from the otherwise pro-market views (health reform was popular in the Valley).