Ben, so far as my experiences are concerned, shipping plantlets rooted in media is asking for failure - hardening off in vitro plants is not for the faint of heart and I can't see very many people popping their newly purchased purple kushie kush OG into a plug and taking it from there.
Your quote however, is a little misinformed from my perspective. Firstly, leaves make poor propagation material in that leaves require one to produce callus and then from there shoot and finally root. I have not been able to figure out the combinations of auxins and cytokinins to bring callus back to shoots. I am reminded of the land before Oss and Orick published a little book on how to grow mushrooms - before then, it was just too monumental a task. They managed to reduce the process to something everyone could do in their kitchen. Sterile conditions seemed insurmountable but they are not. I have never used an authentic autoclave and my pressure cooker works just fine.
Beyond that, there are chemicals available that limit contamination in the medium to the point where I believe no glove box or hood is even necessary. As far as the need for fresh material? Well, I havn't needed such yet but we await final results.
Note what I said though, I would think that a large facilty might use these techniques internaly. I have never believed that tissue propagation would replace seeds and I don't think that anyone would believe such a thing. I am beginning a new experiment (it is nice that this hobby takes so little time, space and money in that I can run multiple experiments simultaniously). I am going to take seeds and grow entirely in vitro from seedling to rooted plantlet. If I can do this, I suspect that I can clone dozens of plants before traditional methods can even yield a single cutting. The trick here is the ability to sex plantlets - I intend to start that this week. Thanks for the ongoing discussion Ben. I would be curious to know what you think of my personal efforts in this realm.