It's not always plausible to open JJ2, especially for the sake of dialogue. Public availability of computers is scarce in most areas. Loading JJ2 onto a public computer with limited availability is also more deliberate. Thereby talking on WWW instead of JJ2 needn't be disincentivized.
Furthermore since I retired from playing ladders, yet I played about 8 years worth of ladders, denying players the ability to communicate about ladder will just lead to a lack of communication. That maybe fine if ladder is supposed to continue with just invitee participants, although that'd really be a change of events.
Granted that this season of ladder appears to have only CDF and T3 jointly vyeing for 200 points, with GPW and CX not participating, and CC not distinctly contending for 1st place. This scenario could be actually optimal for ladder overall, if there's just marginal interest from CC, CX, and GPW. Clans that are most invested into the ladder won't have random other teams competing. Most particularly, if players from T3 and CDF are controlling the rules of ladder, there's no rationale for other teams to compete on the basis of a fair tournament competition, with an (arguably imbalanced) level playing field.
My personal opinion technically disregards the current season; I just don't want to play anymore ladder. I'm not motivated to play so many games nonstop. This thread isn't about me though and my point overall is that -- it's pointless to try and decide who gets to share their thoughts on a topic (such as radar usage during ladders) because that will make you thoughtless and oblivious, and most people would sooner be thoughtful than thoughtless; that much is glaringly obvious.