Wood and Andrew got no where near as much screen time as Spike, We got loads of scenes of a tortured Spike, and spike feeling bad for himself, a whole episode of him killing again, a whole episode of fixing his trigger - that didn't play into the overall season arc that was very underdeveloped, thats two episodes at least that we could have learned more about the potentials which was a story with great potential but kinda fizzled and is now regarded as one of the crappier parts of season 7
I agree that he did have insane screen time, but when I compare it to Angel in s3 for example, we did have an a whole episode of Angel coming back, an episode of the gang finding out, an episode of Angel trying to kill himself, and episode of Angel being poisoned. So Angel to me got just has much screen time as Spike in that season but the writers were able to balance the plots still. To me that means it comes down to two things, either people liked Angel more so they were fine with the fact that he got a lot of screen time, but not with Spike. Or, s7 simply had too many storyline and they couldn't keep up with everything. That's the reason my complaints aren't about too much Spike, but more so about having too many things happening at once. For example, I'd rather them remove episodes like Storyteller than episodes like The killer in me (that was partially Spike central). Ps. I do love Storyteller so I'm glad they had it, but it was still not exactly essential to the plot.
He hadn't really been a main character though, in season 4 and 5 he was a background character who provided comedy, it wasn't till season 6 that he became a main proper leading man character. He got plenty of air time from then on, but thats also when people started to complain that the scoobies stopped interacting as much, and season 6 often tops polls we've done on here as the worst season.
Again, I agree that the Scoobies stopped interacting around that period of time, but again I don't blame Spike. S6 was definitely very dark, and they fact that they had an abuse/depression storyline and an addiction storyline is to me why the Scoobies drifted apart. As much as I wished for s7 to fix that, I don't think the writers really wanted too, as shown by s8 of the comics where the characters are equally drifting apart (without Spike).