The Litre class isn't the ONLY adventure market. It is not a matter of "start with 150 horse or go home"'.
Certainly there is an adventure segment that does not want a 700# monster. There are or have been offerings in the middleweight class from BMW Honda Suzuki, KTM, and Triumph.
The KLR650 was an adventure mainstay for decades. Under 500 pounds, 50 hp(?)
I would think that the Street motor at least has a *chance* of being the basis of an adventure and there's no shame in entering a market with an entry-level offering.
Concur but even at entry level you need an offering that has a reason for being considered ( price, performance, quality, reliability). The HD plate alone will not carry water in this market segment.