I have to respectfully disagree with my friend on this. BRP did the heavy lifting which in a way makes it easier for the next entrant in the market. BRP defined the market and demonstrated the depth of consumer acceptance. They worked out the price points and the cost structure. They created an enormous amount of public interest in this product category. The new entrant could take advantage of all of this. It would not be necessary to reinvent this part of the wheel. They could concentrate of design creativity and covering the ground where BRP has demonstrated weakness.
Another competitor would help both companies in that it would help to validate the legitimacy of this kind of "motorcycle". Remember "real men don't ride trikes", or "trikes are for old men", or "trikes are for women". Another competitor would help to push the reverse trike into the mainstream of the motorcycle world. I think there are a lot of aging Harley riders who would like to have a reverse trike, if only it were a little more "legitimate" - a little more acceptable with their friends.
I for one, would like to see some competition. It could push BRP to better customer service, and may push the dealers to try a little harder. If the competitor were Honda, there would probably be a lot of dealer overlap. I don't know what this would mean.