>>However, it is not an attitude that encourages the open trade in competing ideas.

Sure it is, the reason you think that it is not is because the battle between these ideas happened to be so lopsided you think that that the slabbers were denied the ability to compete.

In fact the slabbers had the opportunity to support their ideas by supporting those dealers who participated in the slab business. If in fact slabbing was beneficial to collectors we would expect that it would gain support and those dealers would benefit financially. Because the idea of slabbing was so widely despised in the hobby those who supported it found that it was unprofitable -- isn't that the way the system is supposed to work?