Overall I get what your sayin' BT but I would say Matt Ionnadis was more 'hoping' he could contribute rather than 'expecting'. They knew when they drafted him that when he had played NT in college he was probably average at best. I think what they are expecting to do is possibly groom him for that role and if it doesn't work out he's still a good lineman for the future. Kinda like they did with Dunbar. There's still a WR in there somewhere, might take a little work to get to it after being on Defense but the move to CB was a crap shoot to start with.
I guess most teams probably should take a lineman (offensive or defensive) with one of their top 4 picks every year. Not all those guys are ready to play out of the box and probably need some training time and the team needs to be prepared for injuries - they happen. If they pick that way - you replace both lines every ten years all else being equal. Drafting - they have overloaded on pass rushers within those top picks but not so much with interior DL.
Top 4 picks:
2008 | 3rd | OT Chad Rinehart | 2009 | 1st | DE Brian Orakpo | 2010 | 1st | OT Trent Williams | 2011 | 1st | DE Ryan Kerrigan | 2011 | 2nd | DT Jarvis Jenkins |
2012 | 3rd | OG Josh LeRibeaus | 2013 | None | CB, TE S | 2014 | 2nd | DE Trent Murphy | 2014 | 3rd | OT Morgan Moses | 2014 | 3rd | OG Spencer Long |
2015 | 1st | OG Brandon Scherff | 2015 | 2nd | DE Preston Smith | 2015 | 4th | OG Arie Kouandijo | 2016 | None | WR, SS, CB | | | |
So none last year but 2 guards and a DE 2015. So I guess you could toss Smith out because he was drafted as an LB but also as a pass rusher.
2 Guards and a DE in 2014. For Trent, same as above. But these guys have played as a DE with their hands in dirt and drafted as pass rushers.
2013 - none but they absolutely needed secondary help and Reed was too good a deal to pass up. Also no 1st round pick. Thomas and Amerson turned out not helping so much.
2012 -1 Guard
2011 - DE & DT. Kerrigan drafted as an OLB but another blitzer and eventual replacement for 2009 #1 pick
2010 - OT Trent Williams. Only 1 defensive player taken in the whole draft (Riley) out of 6 picks.
2009 - Orakpo; listed as an OLB but another pass rusher.
2008 - 1 Guard
So that's nine drafts, 7 offensive linemen (4 since 2014), 5 pass rushers which one could probably list as either lineman or linebacker but they typically played on the outside line.
Eight of those guys still with the team and at least 6 are starting.
Jarvis Jenkins the only interior defensive lineman. They have only drafted a handful below those first 4 rounds and only 1 (Brandon Jenkins) since 2012.
Other than Kerrigan (Smith unknown yet), their pass rushers have lasted for about 1 season before being a flameout.
One interior Defensive lineman during that time with a top 4 pick, maybe should have had another 1 or 2 in there. Hindsight 20-20 maybe but overdue. I wouldn't say give up the pass rushers entirely but three (or four if you prefer) Chris Baker types and you don't need to blitz so much.