Stratford is about 3 miles from East Ham and I think I read that West Ham had some roots closer to Stratford during the early days of the club (presumably when we were Thames Ironworks). No issues with the location from a historical perspective. From a practical perspective, it’s easier to get to from other parts of London/the country because Stratford is a major rail hub, but it’s more difficult to get to for many of our core fan base from Essex and East London, so that’s a bug bear with the regulars. There’s a strong consensus amongst West Ham fans that the move favours casual/new fans and not the regulars.
Regarding the location, another important factor and the only reason I favoured the move at the time, was the presence of Tottenham in the bidding process. How serious about it they were, we’ll never know and it seems like the were bluffing to put pressure on their local authorities to allow them to develop White Hart Lane, but it would have been disastrous to have a Club that is thriving as Tottenham currently are only a few miles away on our turf, so to speak. It would have been very worrying in terms of snapping up the future local supporter base.