There is a generational gap in my play group where half of us are in over 40s and half are under 30s. It actual works great as fresh ideas and wonderment meet with hardened experience and knowledge. As for Critical Role, the kids love it .. the elders wonder why you would watch someone else play .. instead of just playing yourself. This runs beyond just RPG as you can watch people play video games on twitch or listen to people summarize TV and Movies on Youtube... Southpark did an entire Episode on this mentality. i gave up questioning it years ago.
Why we SHOULD care is the fact that the book went immediately to Number on 1 Amazon.. not games of D&D books it was the #1 BOOK on Amazon. CR is huge and Mercer is a good ambassador for the hobby. Its relevant because it is one of the reasons for the resurgence of the hobby. Its one of the reasons that a bunch of 20somethings want to play a 45 year old game with me and my minis.
CR the videocast is not for me, but its good for me.
Ill buy the book.. cuz I buy them all.. but also because the kids in my group want to play with the new CR options