I understand what you are saying, but I think the 3 you mentioned actually could perform at an NFL level. They were high draft picks for a reason but definitely didn't work out.
I watched the Cards the years Lindley was there and he was just awful. In his first season, he posted a very low 46.7 passer rating and threw 7 interceptions compared to 0 touchdowns. He was there for 2 years his first time around and then bounced around the league including a preseason stint with the Pats. He actually started some games in his career including a playoff game!
From his wiki page: Lindley threw his first career
touchdown pass to
Michael Floyd, ending an
NFL-record 228 pass attempts without a touchdown to start his career.
[6] He finished the 2014 season with a 48.4% completion rate, 562 yards passing, 2 touchdowns, 4 interceptions, and a 56.8 passer rating.
[7]
On January 3, 2015, in the Cardinals' first-round playoff game at the
Carolina Panthers, Lindley completed 16 of 28 passes for 82 yards, one touchdown and two interceptions.
[8] He had a passer rating of 44.3 and Arizona lost 27–16.
[8] The Cardinals totaled 78 yards of offense, the fewest in NFL playoff history.
[9]
I still have no idea how he was in the NFL. His coach in AZ was Bruce Arians if that tells us anything.