I completely understand your feeling about sea days. My first priority when booking a vacation (sea or land) is the date and a close second priority is what I will visit.
I did find that my last Seabourn cruise, despite a heavy itinerary, I spent less time than I would have liked to in some of our stops. I often felt rushed and that cruise excursions seemed to go on longer than were necessary (bus trips that seemed to circle the port for the remaining 30 minutes included in price) and that left us with little to no free time before being sent back on board.
I have to agree that for some the entertainment and activities onboard aren't as exciting as relaxing after a full day of touring. There is no mystery as to why some staff called me a 'suite potato' . For me, vacation means new sights, education, and catching up on rest. I feel no shame.
Thank you for your thoughts on your cruise.