The purpose of SIA is to sell your product to vendors. That is stores, places like jibij, evogear, backcountrry and your local ski shop. SIA, is when all the buyers from the retailers from the US and Canada come to see what each company has for next year, and decide what they want to buy.
Since bluehouse, only sells through their online store (at least I think so), there is no reason for them to show up to SIA and spend the money on a booth, since it won't result in an increase in sales.