What are you basing that on? You are saying NFL players of equal height are more explosive than NBA players? I would be interested to see those stats.
Plenty of NBA players could have been NFL players had they wanted to go that route. I can't think of a single NFL player that could play in the NBA.
You have Jimmy Graham who was a basketball player that could never dream of playing in the NBA and now he is a 5x pro bowler. Antonio Gates had a similar situation.
TO was a college basketball player that knew he had no shot of making the NBA so he stuck with football.
There are literally 0 NBA players that decided to join the NBA because they weren't talented enough to play in the NFL.
You see it every year too with HS kids. The kids who just aren't talented enough to play D1 basketball so they decide to stick with football and end up going to P5 schools.
Very few people would choose to be NFL players over NBA players. NBA players make way more money and have much longer careers. Which is why they are able to get more talented players.
The basketball players who transition well to football are basically limited to the TE position, because that's the football position that most closely resembles the game of basketball.
If you combine my playing experience with my coaching experience I've either played or coached on 7 different campuses. On every one of those campuses the biggest/strongest/most explosive athlete was always a football player.
Football players don't play basketball because THEY'RE NOT GOOD AT BASKETBALL. Nothing more, nothing less. Has NOTHING to do with them not being athletic enough. Basketball takes a certain level of skill that goes beyond pure athleticism. The hard part of basketball is being THAT tall and still being able to possess that needed level of skill.
If you're a 6'0" basketball player and can dunk you're considered impressive. (cause you're "short")
Meanwhile a 6'0" football player can dunk off of vert with ease. (@ 220lbs, seen it with my own eyes)
Ever watch the old Footlocker Slam Dunk Contests? Barry Sanders jumping from **** near the free throw line at 5'8". Bryan Cox, a big a$$ Linebacker doing 360's and ****. Jim Leonhard is a 5'8" Safety from Wisconsin who dunks with ease. If he was a b-ball player at that height he'd be considered a dunking icon! In the football world he's just another short MF'er who can dunk, one of dozens.
This is a 6'6" 240+ Defensive Lineman who runs a sub 4.5 forty. So much for them having higher verticals just cause they're shorter.