I've watched this increase in open houses as well and have to admit, I don't care for it either. My daughter has always gotten online and looked up whatever club/ship she was old enough for and learned everything she could (and gotten super excited about it). She loves those clubs. She's older now but being forced into another one for open house is a problem as it's not what we signed up for and in my mind, not what Disney advertises. I'm not saying there shouldn't be any, but in my opinion, they should be few, maybe not even daily.
From her older perspective, she's looked forward to Edge/Vibe as she's gotten older and the idea of having the "younger kids" invade very often I know won't make her happy on her upcoming cruise. I think if you advertise a place for these kids to go, you need to keep it as an area for these kids to go as is advertised.
FWIW as a tween, she may not have been in something Disney labeled as "secured" because she could check herself out according to them, she wasn't allowed to check herself out because of my rules so it was secured as only tweens could come in, and I didn't allow her to come out without texting me and me heading in her direction. But if any adult can come in with a 12/13 year old girl, I'd be making my daughter leave which is another issue that I think is against what Disney advertises.
Again, I think most of the problem comes down to how Disney advertises these clubs versus reality if the Open Houses are increasing. For those that don't want to leave their child without them or that want to be with a sibling/cousin, I think that is a choice you make before you book the cruise and know what you are getting into, and if Disney wants to provide more for those situations, then more play areas or more family activities should be added without making those in the kids clubs more often. Again, a few spread throughout the cruise I can see, but multiple times a day? I don't know about this. I'm glad my youngest daughter only has a couple more years for teen clubs and I am finished if this trend is going to continue.