I think the answer to the OP's question is pretty simple but controversial.

Simply put, some people in Western - and especially American - media have an idea of what it means to adapt something to match their perceptions of a specific and relatively narrow slice of what constitutes a modern audience.  This includes rewriting the "problematic" portions, squashing the component parts together into a pliable dough, and then baking it into a shape that matches their own personal views and fantasies, at great expense.

Fidelity to the books and pleasing the existing fanbase they hired by buying the rights to the IP, could not have been more than 4th priority.  

It's not a simple matter of adaptation.  The stink raised by book fans about the omission of Bombadil in LOTR for instance was minor - most readers understood that it did not serve the core plot and time was limited.

But what has been done in the show is far beyond such runtime-trimming measures.  Fundamental character arcs have been completely transformed, often with even the core themes of those arcs completely changed.  Major plot points which were both important when they happened, and would be important later, are simply omitted or even worse, changed for no obvious reason.  New subplots are added, despite complaining that they were constantly lacking runtime budget.  Core story themes usurped and flipped on their head.  That's not an adaptation.  That's a thorough reimagining, a full reboot of the series with a different author.  Too late to go back now.  It is what it is, and we have to accept that.  I have - I've mostly forgotten the tv show exists, I just happened to see something on reddit this morning that triggered a memory, and I wanted to stop by to see how things were going.  

The show was definitely written and produced for a certain demographic, and if you are among that crowd, then you have reason to rejoice.  I do not begrudge you your enjoyment.  I simply wish that it had not come at the cost of a faithful adaptation, of which we were unlikely to get more than one good shot at this decade, at least.  We will always have the books, and I will need to be content with them.  

Lurker here, want to give you my opinion for what it's worth

big fan of the books, read the whole series multiple times

was very excited to see it on-screen

But nearly every episode featured disappointment after disappointment

I am not certain I have ever seen a hollywood adaptation so utterly massacre its source material

95% of the backstory and tension from the books was just cut

multiple major characters were cut

the entire city of camelyn was cut, which featured some of the best Rand-focused content in the first book, as well as Elayne who is pretty important

accepting the fact that they had to condense it, ok, but then why focus on things that weren't in the book?  we had an entire episode about Logain and the Ghaldeans.  why?  we had a whole episode dedicated to a minor warder and suicide in the white tower.  why?  what's this hollywood nonsense about moraine and siuan having a romantic relationship?  why take the time to add stuff when you are telling me you had to cut stuff because you didn't have time?  the truth is, they didn't have time for the book....but they had time to insert their own personal garbage.  meh.  

most of the main characters barely got any screen time.  

i stopped watching at Flame of Tar Valon because I knew then that it wasn't getting better.  if they would change something so foundational, they would change a lot more.  and from what i'm hearing, i was right.  

took a story to rival or exceed tolkien's works, from which were adapted some of the most classic fantasy films of all time, and pumped out some hot garbage.  thought they were better than jordan, i guess.  well it's obvious they were wrong about that.  i'm just disappointed.  whenever we have a bomb like this there's the fear that "you just can't satisfy this fanbase, so why try".  i get why a lot of you wanted to like it, wanted it to succeed.  i did too.  but not this tam-on-the-quarry-road fever dream.