Having written about all the New Adventures and being in the middle of moving on to the EDAs, this is one of the fascinating phenomenons I've observed. I actually don't think the NAs get less focus from fandom as a whole, but the Eighth Doctor novels have a much more vocal fandom, especially here on Tumblr, and there are a couple of reasons for this.
The most obvious one is niche appeal. Yes, the Virgin books were also very niche, but there are a few key differences to note. Firstly, they had a far greater influence on the 2005 revival of Doctor Who. Two of the three modern showrunners that the programme has had got their start at Virgin and never wrote for the BBC Books lines. Eccleston's lone season was almost exclusively written by New Adventures veterans, with the lone exception of Robert Shearman (and he was pointedly a very hard sell for Davies to get the BBC to accept, having only written a single episode of a cop show produced by some guy called Chris Chibnall).
What this means, in essence, is that there's a clear and undeniable connection between Virgin and the revival, to the point where Series 3 eventually just gives up the ghost and adapts one of the most acclaimed novels in the series.
The Eighth Doctor books, on the other hand... well, you've got the War in Heaven influencing the Time War, but even that's just an extrapolation of the standard fascination with "Wars in Heaven" that you can find in just about every piece of '90s/early aughts genre fiction (The X-Files, Millennium, and three separate Star Trek shows). And pointedly, while the broad strokes of the "big temporal conflict that ends in the destruction of Gallifrey" match, one of the first things we learn in Alien Bodies is that the Enemy is pointedly *not* the Daleks, which clearly doesn't map very well to the Time War. So really, the influence of the EDAs is rather self-contained, and I think this significantly raises the appeal for a lot of fans because, to be blunt, fans generally like to feel like they have unique tastes. The most marginal of Wilderness Years ranges is certainly up there in the uniqueness stakes.
(Consider that we've had, at various points, a television adaptation of a New Adventure, two adaptations of Big Finish audios, and even an adaptation of a DWM strip, but we've never had a direct adaptation of EDA unless you're one of *those* fans who likes to play into the whole "Steven Moffat is a dirty great plagiarist and has never had a good idea that he didn't steal from Lawrence Miles" thing.)
Now this also kind of ties into another tendency I've noticed in fandom, which is to broad-brush the New Adventures as your stereotypical nineties "grimdark" angstfest, while the Eighth Doctor Adventures return to the core of what "real" Doctor Who is.
I've gone on record in my past writings that I have... a lot of problems with this argument, particularly since a lot of the people making it have, by their own admission, never actually read a single NA in their life and are only getting their information second or third-hand. The series definitely started out *very* rocky in that and other regards, and I honestly suspect that Timewyrm: Genesys being the first New Adventure most people will read has done significant damage to the series' reputation because its handling of sex and violence is so utterly juvenile and crass that it really just makes you want to put your head in your hands, go back in time, and tearfully tell Sydney Newman that it just isn't worth it.
But honestly, at their peak (and I'd put the start date at around about January 1995 and largely carrying through to the end of their Doctor Who license in April 1997, though the Benny books definitely continue the solid streak of quality despite being read by even less people) the New Adventures were revolutionary, fresh takes on what Doctor Who could be and, more importantly, really fucking good.
If anything the biggest problem I keep running into in reviewing the EDAs is a basic sense of frustration that the series actively decided to completely jettison the perfectly serviceable storytelling engine that Virgin had painstakingly built up over six years in favour of... well, The Eight Doctors speaks for itself. It's significant that the canonical best books from that early period of the EDAs (stuff like Vampire Science and Alien Bodies, or to put it another way, the stuff that actually had an impact on the line going forward) were almost all written by New Adventures authors, and were largely a case of them porting over New Adventures concerns, because those concerns were actually way more solid than a lot of fans seem to want to acknowledge.
Anyway this is kind of ranty but I keep seeing the whole "The NAs were just angsty pretentious garbage" argument (including in the notes to this very post lol) and I just think it's such a tired and untrue exaggeration that erases the nuance of a really good series.
(And this isn't even me at maximum bitchiness, if that's what you're looking for I could have just answered the "Why don't people like the NAs as much as the EDAs" question with "Because for some God-forsaken reason there are really people in this world who would rather read War of the Daleks and Kursaal than Transit and Damaged Goods.")
