If we understand 'attorney' to be what is now termed a 'solicitor' then it was not then, and is not now, a requirement that they be university educated. (The present qualification for someone who has no degree takes a minimum of six years)
Before the present rules, and well into the C20, it had been possible for an ordinary solicitor's clerk to become a solicitor, simply by dint of long service in a solicitor's firm.
Furthermore, back in the days of Pride and Prejudice, there were few universities. Oxford and Cambridge may have been the only ones in England (I haven't looked). Students there were either the sons of the wealthy and the gentry (if the former their parents may have 'in trade' and frowned upon ) or poor scholarship boys. If they became lawyers it is almost certain that they would have been called to the Bar. The Bar was the 'senior profession' of the Law. Only barristers could become judges . The first years in practice were poorly rewarded, if at all, and so the profession was itself only suited to those of private means.
So, being in the Law was not a matter for snobbish disapproval, but being in the wrong branch of it was.