I'm not a huge fan of the competitive balance implications when a guy is rolling out one active SP...
But you also need to take into account unexpected injuries they are currently experiencing, upcoming real life promotions to their NA players or activations to their DL players, and the competitiveness of their offense.
We've never really had to answer the question of when tanking becomes "tanking", so I don't really know. I think we can all agree that tanking for a high draft / waiver slot is a terrible, terrible strategy in this league, and likely all a team would be doing is setting themself up for a half decade of having no chance at the playoffs.