Honestly, that seems like an overstatement. The same could be said for anything finding its way onto the internet that doesn't represent you at your current best. Maybe if you're a really bad speaker/writer/etc. and, for whatever reason, think you will never get better you should be cautious about doing anything that will expose you online. But I'd suggest simply improving might be a better approach.
In the case of speaking specifically, if you don't start off giving maybe so-so talks at a Meetup, you're probably never going to get better.
ADDED: To your example. So if your first C++ code doesn't hit it out of the park, you should just give up?
In the case of speaking specifically, if you don't start off giving maybe so-so talks at a Meetup, you're probably never going to get better.
ADDED: To your example. So if your first C++ code doesn't hit it out of the park, you should just give up?