Festus,
You ask "why would anyone use silicone????" Dicor lap sealant is about $12 a tube, Proflex is around $10 and sikaflex is upward of $15 depending on where you can find it. Silicone can be had at HD or Lowe's for $2.75 a tube.
As an inexperienced RV owner, I'd be tempted to use the less expensive stuff, after all, it all looks and smells the same.....
As for dealer's using it, seems to me if one could "charge for Dicor and use silicone" one could increase profitability by a significant margin...... Not that any dealer would ever consider doing that... Just sayin'
