It is disrespectful to Steph - he's won 2 MVP's, led his team to a title as the best player and then was the best player on a 73(!) win team.
He's a historically great player who has completely warped the way the sport is played. His impact both in the immediacy and in the long term history of the sport far outstrips those other guys. They are all HoF players (Harden, CP3, Westbrook) but they aren't "inner circle HoF" types. Steph is.
Also lets pump the breaks on Steph's "inner circle HOF" cred. He's had 3 elite seasons, every inner circle HOF guy (not sure what that means but let's go with top 10) had 8 or 9 plus.
Here are Steph's numbers for the past 3 seasons:
238 games: 26.4 ppg, 4.7 rpg, 7.0 apg, 2.0 spg, 49/44/91 shooting, 28.1 PER, 46.1 WS, 23.9 VORP, 9.9 BPM
For comparison here are CP3's numbers in the 2 and 1/2 years before blowing out his kneee:
195 games: 21.7 ppg, 4.7 rpg, 11.3 apg, 2.7 spg, 50/38/86 shooting, 28.5 PER, 43.4 WS*, 21.5 VORP, 9.4 BPM
Steph gets a slight bump because of the MVPs and a bigger bump because of the championships but he needs 3-4 more seasons similar to the 6 Chris just rattled off before we can start talking inner circle HOF.
*WS, VORP, and BPM numbers for Chris are conservative estimates to account for taking out the 7 shitty games he played after coming back from injury later that year.