there is, IMO, a very simple answer to this: Own goals were often attributed to the last person to hit the ball from the attacking team.
The defender (or other, but usually defender) didn't want the own goal and the attacker did - it was a system that suited everyone.
Take a look at this goal by 'rio ferdinand' in the 2002 World Cup - this is given as Rio's goal - that would be inconcievable today, its clearly an own goal. https://www.bbc.co.uk/sport/av/football/21785916
Why has the attribution suddenly changed this tournament?
Edit: I just watched the clip you linked - are you saying that was an own goal because the goalkeeper touched it? That’s just a fumbling attempt at a save. That sort of thing has never been considered an own goal, and wouldn’t be in the current tournament either.
No. Despite not being recognised as such by FIFA, this is clearly an own goal. Even at the time people were surpised by FIFAs decision
"It is hard to define the reasoning behind Fifa's decision to award England's opening goal to Rio Ferdinand since he headed David Beckham's corner away from the net before Thomas Sorensen fumbled the ball back over the line. That was an own-goal and no argument."
Source: https://www.theguardian.com/football/2002/jun/17/worldcupfoo...
"The goal is clearly a Sørensen own goal but despite the availability of TV replays, FIFA officially credit the goal to Rio Ferdinand."
Source: https://www.englandstats.com/matches.php?mid=794
Compared to 2002 there's now much more high-quality, high-speed video being recorded - and soccer authorities recently started using VAR (Video Assistant Referee).
Soccer was slow to adopt instant replays; IIRC the official reason for this was the sport's governing bodies didn't want to widen the chasm between the top leagues and the grass roots game.
As you yourself point out downthread, the award of this goal was disputed at the time, and the guidance hasn't changed. Plus unlike the Ferdinand header, nobody could have thought the cross that Kjaer diverted into his own net last night was a shot on target.
It might be a factor in some goals not being recorded as own goals in the dim and distant days before multi-angle TV replays, but can't possibly explain a spectacular rise in own goals since 2016. Ferdinand-style goal awards are as rare if not rarer than recorded own goals in recent tournament history
Also it makes no sense to attribute a rebound on a defender to the defender (Spain-Switzerland, own Goal by the switzerland defender which is just a kick by J. Alba).
The defender (or other, but usually defender) didn't want the own goal and the attacker did - it was a system that suited everyone.
Take a look at this goal by 'rio ferdinand' in the 2002 World Cup - this is given as Rio's goal - that would be inconcievable today, its clearly an own goal. https://www.bbc.co.uk/sport/av/football/21785916