I think it sent the message Klentak wanted to send, and if the players' response to that was to stop playing for the manager, maybe they aren't the right players. I mean, Mackanin may only be an average manager, but he's not Larry Bowa (ironically), someone so out of tune or over the top that resisting is understandable (or where resisting is what the front office actually wants, a la Dallas Green).
62-100 over the last 162 game is totally by design. They were tanking last year when they should have only won 62 games, and while there may have been a sincere effort to get slightly better this year, it was only slight, and backfired quickly when the "improvements" weren't that great and the returning players either the same or worse.
I'm not much for tough love for its own sake. If they think it would be the best way for Franco and Herrera to reset themselves, and rebuild their swing against inferior competition, great. It doesn't have to be punitive. If they respond to punitive there are other ways to achieve that (because Mackanin is pretty much a softy, despite some thinking he's too harsh on players publicly).
Honesty, it is so bad, that it's really not that bad, is where I am still at. A miserable confluence of bad luck and poor talent feeding on itself. But not necessarily a morass. They could still salvage June. If not it will be time to start trading guys, even if they don't fetch much in return, but can this team even stand to lose the pitching depth?