I think you're overstating the Patriots success in recent drafts. Granted the picks in 2007 that netted Moss and Welker have to be lumped in with the value added to the franchise via the draft, but since 2006 the Patriots have not by any means done a good job of selecting talent with their picks.
Between 2006 and 2008(I left out the 2009 draft because 1 year isn't really a fair amount of time to make an accurate judgement on its impact), the Patriots had 23 draft picks. Of these 23 players selected, only 3 have gone on to earn starting roles with the teams (Mayo, Gostkowski, and Meriweather), 5 are playing in supporting/back up roles (Maroney, Wheatley, Wilhite, Slater, and Crable), and 15 are no longer on the team with a large amount being cut before the end of their first training camp. Furthermore, you have consider how much longer the likes of Wheatley, Wilhite, Slater, Crable, and Maroney will be on the team given their individual performances, and in the case of some ability to stay healthy.
Sure, the NFL draft isn't a sure thing and the chances of selecting an impact player in the later rounds is very unlikely, but you can't have 60+% of your picks go on to not make any impact for your organization. The drafts from 2003-2005 netted us a glut of starters (Wilfork, Watson, Warren, Cassel, Samuel, Mankins, Kaczur, among others).
This team needs a few homeruns in the upcoming draft if they hope to turn it around sometime soon.
You're doing precisely the sort of non-analysis "analysis" that I was bemoaning:
First, the person had said past 3 drafts, and you skipped the last year in favor of 2006, thinking it makes your point look stronger.
Second, you give a nod to Moss/Welker, but you minimize their importance as much as possible
Third, you play the numbers game as if all picks are equal, when they aren't. Here, I'll even incorporate 2006 for you:
Rounds 1-3
2006: Maroney, Jackson, Thomas
2007: Meriweather
2008: Mayo, Wheatley, Crable, O'Connell
2009: Chung, Brace, Butler, Vollmer, Tate, McKenzie
Round 4
2006: Mills, Gostkowski
2007: Brown
2008: Wilhite
2009: Ohrnberger
Rounds 5-7
2006: O'Callaghan, Mincey, Stevenson, Smith, Andrews
2007: Oldenburg, Rogers, Richardson, Hairston, Hilliard, Lua, Elgin
2008: Slater, Ruud
2009: Bussey, Ingram, Pryor, Edelman, Richard
So, a 4 year breakdown:
rounds 1-3: 14 picks, with 10 of the 14 coming in just the past 2 years
1 is a clear bust (Jackson), who suffered injury, meaning the degree of "Bust might have been affected
1 is a likely bust (O'Connell) who was given the "Here's your hat, what's your hurry?" treatment
4 are multiple-times injury players who's future remains unclear (Wheatley, Crable, McKenzie, Tate)
2 are players who've had NFL careers that place them as better than busts (Maroney, Thomas) although not great players
1 (Mayo) is a DROY who suffered a knee injury as a sophomore
1 (Meriweather) just made the Pro Bowl
4 (Vollmer, Butler, Chung, Brace) would grade out as incomplete, although both Vollmer and Butler would seem likely starters next season, pending offseason moves.
So, that's 2 busts (granting O'Connell), and only 2 busts, to this point, out of 14 picks.
round 4: 5 picks
1 is an All-Pro (Gostkowski)
1 is a starter who should be a nickel/dime corner (Wilhite)
1 is a rookie who was an interior line backup that was basically invisible (Ohrnberger)
1 is out of the league (Brown)
1 is a member of the Vikings organization (Mills)
So, that's 2 playing big roles for the Patriots, 1 that's a developmental rookie for the Patriots, and 2 that are essentially write offs at this point, making this a minimum of 40% success for the 4th round
rounds 5-7: 19 picks
O'Callaghan became a starter for the Chiefs.
Smith is in the defensive line rotation for the Broncos
Andrews was a solid special teams player until he decided he'd rather be a criminal
Rogers and Richardson are backups/STers for the Chiefs
Slater is a ST guy for the Patriots who gets the very rare WR appearance
Ingram is the Patriots long snapper
Edelman was the Patriots #3 WR this season
Pryor was an "on again/off again" part of the Patriots defensive line rotation as a rookie this season
That's 8 players out of 19 taken in the back end of the draft that are still in the NFL and contributing, along with another who would still be in the NFL if he wasn't an idiot.
Nothing wrong with those percentages, and I don't think I'm overstating the team's success at all. Once you take in the pattern of the drafts, you see a more successful history than when you just look at raw numbers. That's just the reality of the situation.
And, then, you top all of that off with Moss/Welker. As I said, the problem isn't a high number of misses, because that's simply not what's happening. The problem is that the hits aren't home runs.