Blades is my favourite of the current Rollplay crop of shows, hands-down. So, just to get that out of the way. I love the game, I love the cast and GM, and I love the characters.
I watch it live as often as I can, I've missed I think 2 shows and those were due to them overlapping with games I was playing in. But there are a couple of issues that I find can be detractors:
For one, and yes it's been said before but I'm going to say it again, the late-night start is rough. Not gonna lie, that's a factor for many people, and it seems that maybe the Western-shifted viewers just don't come out for games that are more friendly to their time zones like the Eastern two do?
For another, and this is specifically not a knock on the cast... to a large degree, they don't know the rules. There ends up being a lot of "Wait, what does that mean? How can I? What just happened? How does this work? Why can't I?" questions when the action shifts from the characters (who are amazingly portrayed, I mean c'mon, Aldo...) to the Mechanics portion of the game. When it gets beyond a very basic "I'm doing obvious-action-choice thing X, I have 3 dice, here's my roll" scenario, they flounder. And as the system is not the very binary, laid-out apply bonuses, roll the dice, and beat NumberX to either pass/fail, it's not as quick and simple to stop and do a 10-second "This is the math, you have no more spell slots, or you missed because you rolled one below their Armour Class" and move on. The players need to have more than a passing knowledge of the system and their character mechanics or it's going to bog down into lesson diversions. And for people who have primarily played systems that either are D&D or function in a similar fashion, it's an adjustment. And we're seeing that on screen, unfortunately. I know exactly how that goes, because I see it from my players every Sunday night as I teach them more bits of Blades whenever we run into things that don't work the way they expect. If we were streaming, then every time we once again hit the "Wait, I rolled a 5, how come that's not just perfect, it's not a Fail? How does load work again, I am carrying what? Wait, I mark armour and it's gone? Where's my loot?" questions came up then anybody watching who knows Blades would have that similar reaction of sitting through another session of "Did you read the rules?".