I'm going to be surprised if it makes it past season 3 at this rate.
It's clear that the showrunners knew that they were going to lose many fans of the books due to a number of major changes from the core body of work. That's fine, in theory, if the end result is a fantastic series that draws in plenty of viewers. And in really unsure whether it's been able to that.
I'm not sure whether I'm in an echo chamber, and I'm hearing a small number of very loud voices of mostly book fans who are panning the show, or if it's genuinely been shunned by wider audiences. Anecdotally the few friends I have who have watched Season 1 but who've not read the books have really enjoyed the show. At the same time it seems to have broken several Prime viewers records.
It's really going to sink or swim on Season 2 I reckon, as the more the diverge from the books the louder those dissenting book-reading voices become. I think they've made a rod for their own backs by casting certain actors in key roles, particularly Rosamund Pike - she's a very good actress but the showrunners now need to change an awful lot of the plot in order to keep her the prime character on screen.
Going to be interesting to see how it pans out...