The original work really did need a lot more cutting and other changes for a TV adaptation than a series like aSoIaF which was written from the start in a far more TV-friendly style (not coincidentally, considering GRRM's career).

But yeah, for every change where you can say 'ok, I can see the logic behind this', there are two that make you go 'uh, say what?'.

From a TV perspective, the writers are only one part of the team making the show - important, sure, but less important than the actors and not necessarily much more important than the props and costumes teams, the sound team, editing team, special effects team, location scouts, etc. But for a viewer with half a brain, if the writers screw something up, the best efforts from all those other people are completely wasted. It's rather depressing to watch the mini-documentaries on Amazon showing the work of e.g. the costume department in more detail, because those guys are putting a ton of creativity and effort into their job - but for what, if the writers don't manage to write a story in which those costumes have any meaning?