Yes I totally agree. This kind of post is not acceptable. Each time I see somebody acting like this I send a polite PM to the author of the message and I invite everybody to do the same. Explaining that the level designer might be hurt by this kind of message and that they wish to get constructive criticism instead of short useless message.
Note that a member who has been warned and still post this kind of useless message can be limited in his/her number of posts a day. Just send me a PM.
I know this topic hasnt been posted in for ages but i just have to say that i think it is rude when people post a comment on a level saying 'boring'. Fair enough if you want to give someone constructive criticism to improve their levels eg. its messy in parts, or paths are too slow and waiting is too long, etc...but just saying something bad about the level just because you dont like is rude.
Note that a member who has been warned and still post this kind of useless message can be limited in his/her number of posts a day. Just send me a PM.