Yep - this is pretty much exactly what I was saying.
I recently attempted to deal Swift based on his alleged value.
I’m actually quite high on Swift & believe if he can stay healthy he could actually be worthy of that valuation at some point.
But he’s allegedly worth so much that i figured I might be able to parlay his “on paper” value into a RB + a little extra.
The responses I’d received were pretty similar, “I don’t want Swift, can’t stay healthy, Lions aren’t good, etc”
Personally I feel like he’s got ~80 reception potential (given a healthy season) and a little added bulk should help him between the tackles. Lions are a team on the rise, IMO.
But again - perception becomes reality. Some players get a stigma early on in their career. Swift has only played 2 seasons, yet people treat him like Fragile Fred Taylor for real world valuation.
For what it’s worth, I’m squarely on the Swift side. As 
@barackdhouse suggested, it’s not as lopsided as you had it, and as I’ve said, for a win-now team, Lenny seems like a less risky, higher floor player in a top offense. 
It was an interesting experiment trying to deal Swift. For example, before I set out I checked some calcs just to get a feel for value, and Draft Dominator had Swift worth 289 and Mixon worth 165.
Is Swift ~124 points (45%) more valuable than Mixon?
Which player would a win-now team rather have?
Out of curiosity I just ran Swift Vs Lenny on DD. 289 Vs 134
It’s absurd. And every calc is like this with Swift.
I get where they’re coming from. Age, potential, receptions, etc. Swift may well live up to that. But he hasn’t yet - so any deal involving swift is likely going to look lopsided. FF managers aren’t paying top of the market for him. One JT-type season, with 16 games played & a top 3 finish at the position & we’ll see his RW value spike to match his “on paper” value. 
It’s just not there yet. Kind of like Pitts. They’re basically unreadable players. The shareholder will never get full value for them & the buyers will never want to pay full price as they haven’t actually lived up to it yet.