I think the main problem with the Inhumans is that they'll never be as interesting or significant as the X-Men: they have always been, and will always be, C-list superheroes that barely register in the grand scheme of things, and they've been downgraded significantly from a full-blown movie to an 8-episode series that will probably be the end of it given the reception. There seems to have been little to no planning on how to integrate them into the MCU and make them relevant and interesting, and it feels much like Iron Fist did - as something they're making just for the sheer hell of making it. This is frustrating, because SHIELD actually provided an interesting take on Inhumans and they could have easily built it into this before then going into a spinoff like this.
The sole reason they have a series at all is because the MCU can't go all-out with a proper X-Men series because licensing, and given the amount of effort that has gone into this series - which is to say, clearly very little - I think it's pretty obvious this is a painful filler season in the ever-growing MCU. I mean, even comics-wise before Secret Wars the Inhumans never made that many significant appearances...it wasn't until X-Men licensing issues that they suddenly had a sleuth of (poor quality) comics, anyway.
Part of the problem is that they can't and won't strike out and do something bold and exciting out of fear of damaging the precious continuity of the movies that people actually watch, and why they won't have the Inhumans interact with SHIELD I do not know, because that would be fantastic and breathe some much-needed life into both shows. In a franchise this large and this well-established, I don't think they can just carve a small niche out for something new and expect people to give a damn...especially not when the niche they are trying to carve has already been neatly apportioned to SHIELD and it really does feel like they're encroaching on that. There is literally nothing to sell this series or mark it out as unique.
But I mean, the DCU doesn't give a crap with its TV series - Supergirl isn't even a part of the Arrowverse, and we're seeing crossovers with that. Despite being too short for my liking, The Defenders was pretty good...it didn't do much for Iron Fist, but he didn't feel out of place there, and it might even make him relevant in the future. What this series really needs to make the cast likeable and relevant is integration with the MCU at large. As a standalone series, this is just never going to be much better than it currently is, in my opinion. Hell, even the two Ghost Rider films and the original Daredevil were better than this.