It was widely suspected that Ritchie would be claimed due to his size, his mean streak, his draft pedigree (10th overall to the Ducks in 2014), and his uptick in goal production with the Bruins last season (15 goals in 56 games).
Ritchie clearing waivers like has a lot to do with his $2.5M salary both this season and next. It is probable that teams looked at Toronto's current cap situation and decided that they did not want to do the Leafs a favour and take Ritchie's contract off their hands to provide them some cap relief.
There appeared to be no shortage of suitors lining up for Nick Ritchie's services during the offseason, when the Orangeville, Ontario native was an unrestricted free agent. The fact that he chose the Leafs over other locations had led a lot of people to believe that one of those teams might have put in a claim on Ritchie - especially with COVID-19 decimating teams this season. It never hurts to have an extra body around, especially if that body is 6'3, 235 lbs.
The silver-lining for the Leafs and for Ritchie here is that both Mitch Marner and Pierre Engvall have been added to COVID protocol, so it appears as though Ritchie is expected to be right back in the lineup on Saturday when the Leafs take on the Colorado Avalanche.