Experienced gamblers can have higher chance to get "guaranteed" profit than newbie, non-experienced gamblers, as always true in anything.
Valid point. Most gamblers are newbies who don't know much about RTP and other technical stuff and just proceed to play wherever they want without thinking too much which is why this RTP promo wouldn't really pique their interest.
On the other hand, it would definitely pique the interest of experienced gamblers like me who would try taking full advantage of it.