An advocate does not merely represent a client, he often physically holds the client's money while a matter is pending, whether it is a settlement amount, a decretal sum, or funds meant to be paid into court. That arrangement only works if the client can assume the money is completely safe in the advocate's hands. When an advocate instead treats that money as his own, the breach is not just financial, it strikes at the working assumption that makes the entire profession function.
Look at what each competing punishment would actually communicate to the profession and the public. A reprimand tells lawyers that the first theft of client money carries only a verbal warning. A suspension, however long, tells them the licence to practise returns automatically once the term ends, regardless of whether the trust that was broken can ever be restored. A financial penalty treats the wrong as a business risk that can be priced and paid off. None of these responses match the seriousness of a lawyer converting a client's funds, because none of them protect future clients from someone who has already shown he will misuse the position of trust.
That is why the Supreme Court, in dealing with an advocate who had misappropriated his client's money, treated this as among the gravest categories of misconduct a lawyer can commit, and held that the ordinary consequence should be striking the advocate's name off the roll altogether, not a lesser, correctable penalty.
So the correct position is that misappropriation of a client's money is one of the gravest forms of professional misconduct and ordinarily calls for removal of the advocate's name from the State roll.