There is no contradiction between the two. You absolutely can emphathize with team and protect egos while also discuss efficacy of solutions or correctness.

It is not even hard. Just keep it factual instead of using words like "stupid", "shitty", "crap" or passive aggressivity. Discuss issues before they become big. Listen when they disagree with your assessment - they might have reasons.

I already met enough people who claim to criticise while actually venting their emotions and settle scores with those they dislike.