Tydaddy-- unfortunately, the poster is probably a Marine Officer who is just as immature as his posts reflect. We do have Officers who are far below the power curve when it comes to immaturity, even though they are few in number. When you go to OCS, I can guarantee that you will meet one or two of them, and they will most likely graduate while you see candidates with twice their heart go home. It's unfortunate, but it's a fact of life, and I wouldn't let it deter you from joining.
There's alot of assholes in the world, both in the Marine Corps, and any other place of employment. If theres one thing you owe yourself-- it's to not let someone name "Dirty Underwear Gang" stop you from becoming a Marine.