I've never figured why people think this is such a great idea for any school. Every school that assigns grades ranks its students, and students are the only ones left in the dark by a refusal to publish grade-rank correlations. Employers have no problem figuring out exactly where you stand, especially when they come back to a school every year. Unless you think "ignorance is bliss," this isn't doing you any favors.
I don't think that's entirely true. The people who are most helped by ranks are those who are at the top, and at most schools those are not the students who need the help of the school to get a job. An employer will see "#1" and will know that this is the THE best student in the class, whereas the same employer seeing "A A- A A+ A A A- A" for the first year will be very impressed, but will probably have no way of knowing if this student is in the top percentile or in the top 3% or what.
Employers can tell the difference between a top 1% and a spot-on-median student either by grades and by rank, so in that sense it makes no difference whether you do or you don't have a rank. But the difference between top 10% and top 15% is hard to gauge by grades alone.
So if we limit this discussion to firm hiring (for simplicity's sake), a hypothetical school that places, say, 30% of its class at 'good' firms (by whatever definition) in an average year, might be well served by a no-ranking policy. When rankings are used, firms can see exactly who is and who isn't in the 30%. Without ranks, they may go a bit deeper into the class and get the top 33, 34% people also. On the other hand, a hypothetical school whose reputation isn't good and who in an average year places maybe a handful of people into these 'good' firms might be well served by ranking their students. If a firm is willing only to take the very best people from this school and isn't going to take any risks beyond there, it would help to let them know who these very best people are.