I wouldn't say that ATWT was difficult to write for, but I definitely agree with the assessment that after Marland died, there didn't seem any great writers after--I don't know why but even when there were good storylines in the decade after, the best ones lacked complexity that ATWT used to be known for. And those various story threads, that at first seemed unconnected, but would eventually weave together to create a fuller, richer story...ATWT couldn't find that again.
I once asked the question of whether the Writing Staff at Soaps plotted out storylines on a big whiteboard and specifically writing out dramatic/character arcs and structure. Some type of blueprint so that, in case of anything, everyone knows the direction in which each and every character is meant to 'go'. I just got the feeling that after Marland died, for example, the writers left to write had no idea where some characters were going nor where they were meant to 'end up' dramatically.
I also agree that good writing should've been possible throughout the years but great writers seemed in short supply-- at least the ones that wanted to write for Daytime television. I know that ABC Daytime had a program but it was mainly for Production, with an emphasis on Production Assistants and Associate Producers, with a very light footprint in terms of Writing. CBS didn't have anything that I could see beyond a few internships.
I could never understand why there wasn't more substantive outreach to Writing Programs. In the mid 00s, I graduated from a Writing Program (I won't mention which one) and during that time I saw solicitations and announcements to submit work in consideration of some Theaters/Play Groups/Festivals, for Short/Indie Films, TV programs (mainly for Children's TV shows like Nick, which I had no interest in) and once I even got a solicitation to write a script for a Porn film (I kid you not). I never got any announcements from a Daytime Soap.
Perhaps if these shows could've lured some talent fresh out of Writing/Film schools to apprentice with the greats of the genre, inside of keeping it such an insular small group, there might have been a better chance of that continuity of good, compelling storytelling. And each subsequent generation may have continued to bring contemporary issues to the fore instead of the re-tread and re-hash of content we have now (rapemances, numerous back from the deads and Baby Paternity to get Married storylines).