I can't speak for others, but for me I catch a lot of fish on our vacation lake with the tactics I use, and I have grown the bag of tactics I have over the years, and I am still trying to add more. I have many finesse presentations, but they all get more casts per hour than a Senko. For my personality quirks, that works for me and I probably could fish a Senko but not for long without getting board.
The vacation lake is also a very windy lake and I fish out of a 16 foot aluminum boat that makes holding stable difficult. I also fish reeds a lot and in the wind weightless baits and true Ned rigs are difficult to fish in those conditions. Often I have to up the Ned rig weight to put the bait where I want it. The only time I could effectively fish the weightless senko is sunup where 4 of the 7 days it has been calm enough to effectively fish lighter baits around vertical cover. Who knows if I fished different cover and wind conditions maybe I would be using it more, but since this is the lake I hope to retire on it may not be in the cards.
I know they catch fish, but the drop being slower and the twitch and then glide of the bait taking longer than a weighted plastic is what doesn't suit my style. If I am not catching fish I do what I need to do to catch fish, longer pauses, etc until I key in on what they want. Last year it was letting it drop and shaking the bait in place while other years it was letting it sit. I just haven't grabbed a weightless senko or other stickworm to put them in the boat. I have used a swim senko on a 1/4 slider head and let them sit on the bottom for 5 seconds to catch fish, but to me the swim senko is a completely different bait.