I'm not defending Groulx, but this critique is ridiculous.
He came on in 2016-2017
Anderson at that point was 35, and had his last great season. His SVP over the next few seasons was around .900. Probably just a bit over. We're talking about a goalie between the ages of 36-38. We're faulting Groulx for age?
Hammond was an absolute flash in the pan. He followed up his cinderella run with a .914SVP and 2.65GAA, though, and then got injured... he played 31 games over the next two seasons. We're faulting Groulx for injury?
Condon, too - this guy was a .900SVP goalie before he came here, and then he posted a .914 in Groulx's first season. Then, well, he went back to .902 and, like Hammond, suffered a major injury that limited him to 14 professional games - 2 NHL, 8 AHL, and 4 ECHL. Again - we're faulting Groulx for injury?
Then we have Hogberg, who steadily improved throughout his time in the AHL and then had a pretty impressive showing last season in the NHL. 4 games in behind a terrible defense, he's been ruined by Groulx - the only goalie coach he's had at the North American pro level, who oversaw his development from mid 3rd rounder to NHL goalie?
And what about Nilsson? Nilsson came in and played his best NHL hockey behind the worst team he's ever played for. If not for his injury, he's on our team right now.
As for Murray... this is a guy coming off a season in which he was outperformed by .022SVP by a guy who really isn't that good. Now he's behind a terrible team and getting lit up, and Groulx is supposed to have ruined him? Everyone knew Murray had mechanical issues that needed to be sorted out. He's been here for what, a month?
I have never wanted Murray because I don't think this is the right environment for him to build his game back up, but if I'm a goalie coach I'd be thrilled at the chance to work with him. Early in his career, especially, he was a goalie coaches dream. Very few guys rely on mechanics more than Murray, and his fix will be in getting back to the fundamentals. If Groulx is the guy to do it or not is a question I don't have the answer to, but blaming him for not immediately fixing complex, deeply-seated issues is absurd.