As mentioned earlier, if you don't enjoy metal you won't get Steve Harris. Just like if you don't enjoy jazz you won't get Jaco, or if you don't like funk you won't get Bootsy.
The fact is that he inspired thousands, maybe even millions, of kids (me included) to pick up the bass and do more than just plunk along on the root and/or just copy everything the guitars do note for note like Gene Simmons or Michael Anthony. When I heard Moonchild for the first time it was a literally life-changing moment, and I say that with zero exaggeration. I decided that I wanted to play bass after hearing that song and 21 years later I'm still at it. Steve, along with Cliff Burton, redefined what the bass was meant to do in metal - they used their position as the bassists of the two biggest metal bands ever to do that. Geezer had the groove and creativity, then Steve and Cliff came along and added power and speed to that.
Being the primary songwriter for Iron Maiden means the bass is the root and anchor of the songs. His playing is the pulsing heart. And even on the songs he didn't write (Powerslave and Wasted Years come to mind), his basslines are clever, melodic and well thought-out. He was revolutionary. Surely that boosts his status immensely.
Is he technically one of the best bassists ever? No, I can think of 10 players not on that list who are better than him off the top of my head. Is he one of the greatest ever as described in the list? You betcha.