Danny Richie of GR Research designs and sells both OB and sealed box loudspeakers and subs (in kit form). He has used the same drivers in both applications, and makes no bones about preferring the sound the drivers make when used open baffle. That preference is not a result of design difficulty, but of achieving maximum transparency, greatest soundstage depth, and lowest coloration.
Danny knows some stuff and is probably capable of designing a box speaker that can blow someone’s socks off too. But, the latter would end up costing more than what his target market would be willing to pay (i.e., diy guys fishing for high value stuff and very modest pricing).
He is a small business/ lacks the resources of the bigger gigs to keep prices down. OB is the easier way out to satisfy his targeted customer base/modest price bracket requirement.
My earlier comment was hinting at some other coaster clowns (not Danny) who know absolutely nothing about speaker design...but seem to be minting with their open baffle overnight speaker "expertise/extravaganza"....Am sure the next venture for these guys would be "high end" cable design...very easy to become a high end cable design expert PhD overnight as well.