Kane scored 1.76 p/60 at 5v5 in his D+2. Lafrenière scored 1.66. I realize that's one example, but it's not like this is unprecedented even if it's rare.
Also, the early season shooting percentage woes are affecting everyone in the top-6, which included Lafrenière and Kakko until recently. Kreider, Zibanejad, and Trocheck have each never had a full season with shooting percentages as low as what they have to this point this season. In particular, the number of high quality chances Lafrenière has set up this season that haven't resulted in goals reflects this.
There's no doubt that the two of them have been disappointing and I'm not trying to say otherwise, but patience is honestly the most reasonable position to take with them at this point for two reasons. One is that their talent is pretty obvious and the other is simply this: what other choice is there?