I'm a good one to chime in on this, as I usually cruise Radisson now, where tips are included in the fare. But not long ago, I cruised mainly RCI, with a bit of NCL and similar lines thrown in. In some respects, comparing Radisson to these lines IS like comparing a Ferrari to a Ford --- but it is not really so in the area of service. We had no problems with mass market service, and that is not the reason we moved up. We moved up because we tired of the crowded conditions and the increasing nickel and diming. And I don't include tips as the nickel and diming which I found objectionable.
We always found service pretty great on the mass market lines, particularly RCI. Darn close to Radisson levels as far as waiters, stewards, and all are concerned. While Radisson has one crew member per every 1.5 guests, and RCI has 1 crew member per every 2.5 guests. it is possible that the RCI service crew were working even harder! Accordingly, we always tipped them, and tipped them well, as they did such a good job. I see no reason why adding $70 to $100 pp on a 7 day RCI cruise would disrupt RCI's marketing position. And (perhaps after an initial shock) I think both guests and crew on lines like RCI would like such a system,.