Couple of thoughts-
I do feel for Linkara when a season just fails to make the team engaging. I don't agree with all his ideas (not sure why Turbo should have been about the existing team learning to juggle Ranger duties with adult life) but I always agree when he comments on teams not really displaying heroic qualities. As he's mentioned many times, my vision of a Ranger is someone who deserves the powers because they would be a hero to the best of their ability even without them. Yeah the costumes and gadgets are cool but the moments that stick in my mind are always when a ranger or team is outgunned but still gives it their all to save the world. Even the cheesy first movie got that concept right. A season that gives us boring mannequins that just wear the powers is so boring.
I am disappointed in his thoughts on the costumes though. He's made it very clear that he doesn't care what the sentai does but I think Gokaiger had a brilliant concept with the team being human-like aliens from an already conquered planet who 'pirate' the past powers and slowly grow into caring about the virtues super sentai champions. Super Megaforce just keeping the pirate motif for stuff and not actually doing anything with it is a huge waste. I feel the same way about Magiranger vs Mystic Force, where the family connection in the Japanese series had much more going for it then 'RED IS THE ONLY ONE WHO MATTERS' in the Power Rangers take.
Also think Gokaiger made the 'why is no one else helping?' stuff make more sense since, from memory, wasn't the initial Legend War the opener and we're told the assembled teams lost their powers in exchange for unleashing a sure kill attack against the initial armada?
Keeping the sentai teams in is stupid. Yes, as he points out and many of us said at the time it's easy enough to say these are alien teams or ancient rangers. But they have no significance to an adaptation that started with Zyuranger. It might have been cool if they'd kept in an appearance by the original sentai team and explained with some mildly meta dialogue that we were seeing the original team that all Rangers across time and space were spawned from....but they didn't do that. There doesn't seem to be any reason beyond, as the video says, a weird mix of lazy and sentai fanboying.