Well, it's doubtless that some will prefer other bikes. I think that is to be expected, given the differences in consumer tastes.
But, RE only has to have a niche. I don't think anyone is expecting RE to surpass Harley-Davidson sales volume. If the new RE can maintain a similar market penetration here in the US, as it has in the past, then that's a good start and it can work on building up from there.
The main thing is that the bike visually appeals to a certain demographic of sufficient numbers, and has reliability and performance within the reasonable expectations of the people who purchase them.
The people who buy them will obviously have liked the appearance, and as long as the bike gives them no real reason to start hating it, then it will be fine. The owners will then speak well of it to others, and the sales volume will start to increase as word gets out that it's a nice bike that costs less than many other choices, and offers some unique qualities.
That's all it really needs to do.
I'm sure that there are Bullet owners right here on this forum board who would have paid $2k extra to have 70mph highway cruising ability, some extra power and torque, and no reliability worries.
I personally feel that the Sportster is not in a category that competes with the RE, because of the differences involved.
The Bonneville may be a closer comparison, which might appeal to Brit bike buyers seeking choices, and the RE could face competition from the Bonnie for those purchasers who prefer more power and a twin.
I think that demonstrator rides are important. The Bullet is perceived as a very slow bike by uninitiated consumers, because the spec-sheet numbers for hp look very low. Assumptions are made that the Bullet is barely above a mo-ped, for that reason.
Once a person rides a Bullet, and sees that it is quite adequate for fun road riding, then the apprehensions of low power tend to evaporate.
The spec-sheets work against the Bullet severely. They don't tell the story.
It is up to the dealers to give the customers a chance to ride on a Bullet, so they can see that it is a real motorcycle in the real world, and not a mo-ped.
If a person likes the appearance of a Bullet enough to come to a dealer to look at them, and gets to experience how fun they are to ride, then the spec-sheet info is a thing of the past, and the consumer makes the decsion based on real world performance instead of a preconceived notion..