Okay, so I get how loaded of a question this is.
ED had plenty of issues during his tenure -- including injury, questionable arm strength, and bouts of inaccuracy. But he also proved his mettle on the field. His junior year, which didn't go as well as expected but could have, he was unstoppable against FSU... with a broken foot. He kept us in the game against top 10 ranked [at the time] Miami. He kept opposing DC's up at night, even despite the throwing inconsistency.
At the end of the day, he also has his career completed, and now in historical retrospect. I think that some will gloss over the problems / inconsistency he had his senior year. But then he stepped up against NC State, he led us to 10 wins and a bowl win, etc. He deserves the accolades he's earned, through the lens of how things played out historically, because his accomplishments happened on the field. We as fans experienced the resurgence -- Eric wasn't individually responsible for all of the on-field success [Tommy CERTAINLY contributed to last season's outcomes, as well], but he deserves the accolades of the job accomplished.
Tommy DeVito is at the beginning of his career. He had ups and downs his freshman year, but won games against FSU and UNC, contributing to that 10-3 campaign. He also struggled intermittently. I think that it is valid to question his feel for the game, given what we've seen transpire on the field. I also think that there have been times when he's played better than the team has "perfromed," but gotten a lion share of blame for the losses.
I think that some of the criticism Tommy has gotten this year is warranted. He hasn't shown the playmaking instincts we'd hoped for. But he's also working behind an OL that has struggled IMMENSELY to both pass protect, and to open holes in the running game. Not all on him, but some of it is. BUT it isn't difficult to envision that he'd perform better with a solid running game, and a line that doesn't have him running for his life most of the time.
I also think back to Ryan Nassib's career -- not that TD's capabilities are exactly the same as Nassib's, but he was maligned by a portion of the fanbase throughout his career, then was stellar during a senior campaign where he had an OL that gave him time to throw.
So, in the main, both aspects are true for DeVito -- he's made some dumb plays, he's been squirrely behind poor pass pro, but he also has been intermittently good -- especially in terms of YPP most games, and in terms of efficiency some games. I also think that some fans point to stats as "evidence" of him performing well, when the results on the field have been subpar. Wishful thinking / rationalization? Probably to some extent.
His story is also still being written. This year sucks, and barring us winning 3 of the last 4, we aren't going bowling. But maybe being thrown into the fire will be beneficial, and maybe behind a stronger OL next year [with OTs like Vetterello and Bergeron, with experience under their belts] he'll have a better running game and more time to throw.
Summary: it is too early to compare ED to TD. If TD rights the ship this year, if his performance is better the next two years, etc. then these growing pains might seem "worth it." Time will tell, but I think that in two years, TD's accomplishments might look a lot different in historical retrospect... the same way that ED's do.