If someone wants to get wasted and isn't being an idiot to others then it's not doing anyone any harm but when you get those types that are actively trying to promote the image of themselves as someone that drinks a lot to seek social credibility then it looks a bit cringe.
The thing with getting wasted is it's not hard to do, you just have to spend the money on buying enough alcohol and then drinking it, and it's not exactly rare either, if you are a student then loads of people are doing it so it doesn't mark you out as anything special. So if you're purposefully uploading pictures of yourself with a beer or looking smashed to promote a lad image (or girls do it too to promote a vodka party girl image), or you are always trying to drop stories in to conversation about how you were "totally wasted", "passed out on the bus home and ended up stranded 30 miles away LOL" then it loses value quickly, people don't think you're a cool edgy charismatic personality they just think you're trying to use alcohol to give you a better social image.