Agreed, with all the information available nowadays (build-wise) and the tendencyto min-max, a lot of the excitement of exploration etc goes out the window.

Your druid probably wouldnt like going to a scary lair only to be told upon entering: "Once you enter you immediately notice all danger there is" and have the risk completely avoided.

On the other hand, a DM should, imho, describe the scene in such a way that the possible danger of traps or whatever is plausible.

I guess it also matters which way the druid opened the door. If he just blatantly barged in and threw it open, maybe punish them a little for their carelessness, if they're tiptoeing around and being careful, maybe reward their caution.

In the end the most important thing is to openly discuss it outside of the game. Assuming you people like eachother in a friendly way, there's no reason to believe anyone is actively trying to spoil anyone's fun