I'll take a dissenting opinion all around here.
(1) I see no reason why there is any reason to add a fixed amount to any player. If an owner wants to burn a roster spot for a A+ arm, even if the player costs only $200K, that seems to be a fair trade-off for having one less pinch hitter or runner. Prior to WIS adding this salary ajustment I never-- not even once-- hear/read a protest that it wasn't fair that their team's running game was spoiled by a scrub.
(2) There are a lot of other cheapo specialists that are often used and WIS never adjusted these salaries. Wilson Delgado at $250K is a great pinch hitter but has almost no other use. Ditto for Clyde Sukforth and Howie Clark at $200K each. I often draft Tim Flannery and John Dodge as defensive replacements if I am short PA at 2B or 3B. Besides strong-armed catchers there are no other flat adjustment to player salaries. Again, I do not see why the adjustment is necessary.
(3) I think the concept of spead teams is a bit flawed. Don't get me wrong: I am not a big fan of the home run in baseball and I think small ball is more exciting. However I think it is wholey unrealistic to think that the best base stealers could have stolen even more bases than they did in real life against a bunch of great throwing catchers like (a young '75) Gary Carter. I watched guys like Vince Coleman and Tim Raines play. I know that in their best stolen base years (especially Coleman) they ran just about as oftern as they possibly could. If WIS would dial back the utility of sb specialists like Coleman, the utility of great catchers would also be diminished and there would be no reason for a fixxed adjustment.