Even if it is true that this student everyone is discussing is undecided as to what their future career will be - why is that so offensive to people?
If you are a good student with great employment prospects, which I am assuming this person is given the positive response they received from firms, there is nothing wrong with being honest enough with yourself to admit that you really don't know that much about each of the firms and one of the best ways to find out what a firm's culture is like is to actually speak to representatives of the firm.
Eg - I had an interview with a firm a year ago and from the job ad, their website and the opinions of other solicitors i gained a very favourable impression of the firm. First interview was great, the HR manager was really friendly and informative so this further confirmed the view I had of them. But, second round interview was shocking! They were rude, asked questions that it is unlawful and/or immoral to be asking, everyone seemed terrified of the principal solicitor, the office was disorganised, staff members were incredibly discourteous to clients etc. Upon returning home from the interview, I received a call asking me to come back that day for a 3rd round interview and then was abused over the phone and told I was ungrateful for saying that I would not be able to get back there in time as I had only just gotten home and they wanted me back there in less time than it took to travel there. So of course, I refused and crossed that firm of my mental list of places to keep in mind for work
There's nothing wrong with keeping your options open and informing yourself as greatly as possible, provided that you are doing so in an informed way and have thought it through
I think it's only problematic if such a student was unsure as to their future direction alongside having poor marks, lack of experience, lack of extra curriculars etc etc as in that kind of situation, your options are a bit more limited so you do need to be more aware and committed to a future direction.