It's not just "people" that say this, it's nearly every NFL talent evaluator or former FO person working in the media. I listen in Sirius NFL constantly and most analysts there share the feeling - QBs need time to develop.
EJ missed critical time in pre-season AND in the regular season, he needs a full off and regular season to see if he develops, IMO.
And the "good" news is, if he's really as bad as some want to believe, we'll be in the position to draft another top QB next year. I wouldn't be against that...
Someone above mentioned Mayocks commentary on Bridgewaters Pro Day, it sounded brutal. He said he's seen tons of Pro Days and this was awful - aiming the ball, not anticipating throws, missing guys 5 yards away, and that's in a controlled environment. If guys fall this year, it'll be because they aren't that good.