I believe that this pick was made right at the tail end of the era of the Bruins/Ducks bully style. The roster building meta was hinged on stacking your line up with big, mean, physical players that would overwhelm the opposition. It was a slow style of play that teams were trying to copy, but quickly faded. McIlrath would have fit in fairly well had he been drafted like 5 years earlier.
I think the Ducks were pretty much done as a goon squad at that point since guys like Pronger, May, O'Donnell, etc. were long gone. Otherwise, I agree.
As for the 5 years. You're probably right. McIlrath coming in at the 2005 draft would've had him coming into the West when teams were trying to battle off the Ducks circa 2008-2009, or in the East which remained pretty rough for a couple of seasons after McIlrath
IMO, you'd need to make that 10 years. Put McIlrath in the 2000 draft and teams probably hope they luck out on an eventual Pronger/Stevens type as the ceiling, but are certainly OK if by the lockout they end up with some Belak type part time enforcer/sheltered #6/7D.
IIRC, the Rangers felt like they wanted to focus more on getting their next Beukeboom instead of Leetch. Guys like Redden and Poti had flamed out pretty terribly as high end offensive D types, but they also had guys like Staal, Gilroy and Girardi on the team with some perceived upside, and Del Zotto (#20OA in 2008) and McDonagh (#12OA in 2007, acquired a year earlier) in the system. I think the Rangers tried to make sense of it in that toughness was still needed in the East, especially in the Rangers division. They were coming off a season where tough guy duties were handled by a washed up Donald Brashear and not-so-NHL-worthy Aaron Voros... Remember a week after they made this pick, Sather went out and signed Boogaard to 4 years of term... That was when the Flyers were still the Flyers and had Pronger, the Pens iced Matt Cooke and guys like Adams, Rupp, Godard and Engelland, and the Islanders were a gong show with guys like Martin/Gillies/etc. who would go on to absolutely goon the hell out of you for giving a 3rd line winger some whiplash or laughing at Rick DiPietro's misfortune... Outside of the division, you had the Bruins climbing to the top of the league while playing tough with the biggest Dman to ever play the game a year removed from winning a Norris, and eventually the Sabres would go out and get John Scott to avenge a hit from Lucic on Miller.
The pick has a lot of similarities to when the Avs took Scott Parker in the 1st round. Both were physically already huge and absolutely murdering guys in junior and could at least quickly step in to provide that type of presence. However, by the time McIlrath had run out of waiver exemption and shown he wasn't a worthwhile defender in the AHL, there was no longer much need for his ability to beat people up...
If you want a good read, there's a thread from way back where some holier-than-thou fancy stat cherry picking Rangers fan declares McIlrath better than Fowler. The same fan also heralded Brendan Smith as "world class".