Speaker designers are driven by their education, experience, practice, and their personal sense of hearing, and they're sometimes also biased by what they or their marketing partners believe is consumer preference at a certain price point. How each speaker designer arrives at his product goal creates a whole variety of synergies, dependencies, and sound profiles. None of those resulting designs are wrong or hard to drive unless the home audio consumer market stays away from the product or the reviewers kill it.
Basically today, there is so much speaker choice in the marketplace at literally all price points that something perceptibly hard to drive is essentially a side issue because there are always identically excellent choices that are ideally suited to someone's existing amplification and room and physical cabinet size preferences.
Suggesting that "hard to drive" is a no-no implies that development decisions by speaker designers should be limited. I think that's counter-productive.