What's not to like about a 7'1 guy who can pass, dribble and shoot from the perimeter?
I'll share a little secret with you -- you actually have to be able to play a position in the NBA in order to stick around.
You know who else was 7 feet and could "pass, dribble, and shoot from the perimeter"? Yi Jianlian. Jan Vesely. Heck, even Kelly Olynyk.
You need to be able to defend a position. From all I've read Bender's biggest selling point is his ability to guard multiple positions.
Had Jan Vesely been able to shoot at all he would still be in the NBA, had Yi been able to play any defense at all he would still be in the NBA. The scouting reports indicate that Bender is a better defender than everyone you mentioned.
The idea that people players need to fit a specific position archetype to be successful has been disproven by how often players switch and how many positions play on the perimeter. The idea of position archetypes is antiquated.
This is literally the first time I hear this. The scouting report says he has a "great low stance" on the perimeter (this doesn't mean he's anything close to able to defend quicker NBA forwards), and questions his inside defensive presence, rebounding, and athleticism.
The myth of Dragan Bender is by large perpetuated by the fact that no-one has really seen him play, let alone against any sort of meaningful competition. Which is in itself a red flag.
I don't understand why people keep bringing Porzingis. Porzingis was a rotation player in the ACB for two years before he was drafted, and the ACB is just a tiny bit better than the Israeli league 
So this is what I posted on page 3 of this thread but there is some ambiguity to it so I understand the difference of opinion.
Bender stands at 7-1 but is very agile for someone his height. He can sprint up the court to finish with power in transition and has flashed second jump-ability to fight for tip-ins on the offensive glass, when a tougher big man doesn’t erase him out of the play completely with a physical box out.
But Bender’s mobility is perhaps even more promising with regards to his potential defending in space. Obviously, he is not suited to pick up speedy point guards on switches and have to navigate ball-screens, but Bender has proven able to bend his knees to get in a stance, move laterally and keep pace with less athletic wings like Alessandro Gentile and Mindaugas Kuzminskas in isolation. His 7-2 wingspan makes it extremely tough for an opponent to shoot over him off the bounce without creating a good amount of separation first.
As a help defender, Bender can cut off dribble penetration containing the pick-and-roll as a big and has long strides to crash inside to bump a big rolling to the basket and then closeout to a weak-side spot-up shooter. More critically, he has often been able to run the shooter off the 3-point line and maintain his balance to defend the dribble drive.
The last paragraph indicates he can do anything you would need of an off ball defender in a team defense. This report also indicates that his combination of length and mobility allows him to guard some perimeter players as well as some post players now, which should only improve as his body develops.
Reading this report indicates that you have a player who will be able to play any type of pick and roll coverage, help his team by closing out on help defense and eventually bother shots in the paint due to his length. That he exhibits all these traits as an 18 year old is pretty impressive and shows flashes of what is to come.
Here is a quote from Jonathan Givony on comparing Porzingis and Bender
How do you find a 7’1″ kid that’s 17 years old, that is skilled with such a feel for the game like Dragan’s? It doesn’t exist. Compare where Dragan is now to where [New York Knicks No. 4 pick] Kristaps Porzingis was at the same age, and there’s no comparison. Bender is way ahead in terms of how polished he is, creativity, versatility and his body. I was watching some of his games from preseason in France and Israel, and he is huge.
His body made a huge jump this summer. Every time I watch him, he is better, stronger; his jumper is better, his ball-handling, he runs coast-to-coast, dishes off. … NBA teams will fall in love with him.
When comparing the two you have to remember that Bender is coming out at the age of 18, where Porzingis came out at 19