I think that's slightly harsh, Bielsa is a good coach doing very well. Escaping the championship is a great achievement and so is avoiding relegation. The main reason I would be very nervous if he was here though is the backroom setup he demanded when he joined. IIRC he is paid a relative fortune but then to offset that he personally employs the entire backroom team, rather than the club doing it.
The reason that would worry me is that when he leaves it will be scorched earth, zero continuity and Leeds will have to build an entire new backroom staff structure very quickly. With his track record of stubbornness and fall outs that could happen with relatively little warning.
Our current set up is much more modular. If DS left then I assume that ROK would follow but everyone else would be fairly likely to remain. That would mean we could plug a new coach in without having to rebuild the entire footballing staff of the club.
And also, for all Bielsa's success at Leeds, when DS started with us the were at the top of the Championship (in large part thanks to Bielsa) and we were about 15th. Any extra money we've spent to get to where we currently are has pretty much been offset by the extra year of PL revenue we've managed to get ahead of Leeds by being promoted instantly as well.