Even if I had 100 bitcoins I would still earn from signature because why turn down free coins? Its still the best and easiest way to earn bitcoins after all.
well it depends on the type of person who wear the sig, not everyone will continue with it if he own more than 100 bitcoins
btw i understand what do you say, if this is for free and we didnt hurt anyone, why not to continue?
about the main question "Why You Should Never Sell Your Bitcoins Ever", i have a simply question, this is just because most of us ( the bitcoin owners ) really think that in the near future the price will raise a lot, thats all
at least thats my case.