Speaking as someone who hasn't seen the Defenders yet because it looks kinda meh to me, I'll say that my lack of excitement has to do with how poorly they have sold this crossover series so far. It looks like something that only exists because someone decided this crossover has to exist. There's nothing inherently appealing about the proposed storyline and everything in the trailer looks like more of the same. It's easier to get excited for the potential the Punisher series has in terms of character arc, or the next Daredevil season which could be Born Again, etc. With Defenders at this point it feels like whogivesafuck, and after talking to friends who have seen it, it sounds like the storyline itself is just more cockteasing for a "real threat" somewhere down the line.