"The other side" criticized Trump for what he said. They did not impugn the potential of chloroquine. This issue is only, "What did the president say and should he have said it".

No responsible person should offer unproven medical advice IN ANY WAY. And no medical professional should do so unless they have multiple reliables sources to support their advice.

Trump failed on both of these points. If chloroquine turns out to fail, he'll surely promote more possible treatments again and again, thereby whittling away public trust and hope, over and over. That's terrible leadership, and rightly merits criticism from everyone who gives a damn, not just "the other side".