A former Sony developer has said the great PlayStation 4 cross-platform block is all about the money.

John Smedley is the ex-boss of Planetside 2 and H1Z1 developer Daybreak Game Company, which changed its name from Sony Online Entertainment in 2015.

In a tweet referencing the fact those who used their Epic account to log-in to Fortnite on PS4 can't use the same Epic account on other consoles, Smedley said Sony's controversial policy comes down to money.

"... when I was at Sony, the stated reason internally for this was money. They didn't like someone buying something on an Xbox and it being used on a Playstation. simple as that. Dumb reason, but there it is."

In the context of Fortnite, this would mean Sony doesn't like the idea of a player on Xbox buying a character skin via Xbox Live (and in the process handing Microsoft a 30 per cent cut of the revenue), then logging in to the PS4 version and being able to use that same skin on their persistent, cross-platform character when playing the game on Sony's console.

Smedley's comments shouldn't come as a huge surprise, given comments made by Sony executives in the past about cross-platform play. Back in E3 2017, PlayStation global sales and marketing head Jim Ryan told Eurogamer Sony's policy is "a commercial discussion between ourselves and other stakeholders", before suggesting it was also about concern over children playing online on other networks through their PSN accounts.

The issue of cross-platform play was thrust into the headlines again during E3 last week when Fortnite hit the Nintendo Switch, and players found they could not use their Epic accounts if they had already used it to play on PS4.

Sony has been roundly criticised for blocking cross-platform play with rival consoles when it comes to Fortnite and other games.

Sony has been roundly criticised for the situation, with the cross-platform issue hitting the mainstream media in recent days.

Sony, though, shows no sign on caving on this. Last week the corporation issued a statement that failed to address the issue. It's below:

"We're always open to hearing what the PlayStation community is interested in to enhance their gaming experience. Fortnite is already a huge hit with PS4 fans, offering a true free-to-play experience so gamers can jump in and play online.

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"With 79 million PS4s sold around the world and more than 80 million monthly active users on PlayStation Network, we've built a huge community of gamers who can play together on Fortnite and all online titles. We also offer Fortnite cross-play support with PC, Mac, iOS, and Android devices, expanding the opportunity for Fortnite fans on PS4 to play with even more gamers on other platforms."

Sony's policy comes despite what seems like a genuine desire from the development community to make cross-platform play happen. At E3, FIFA creative director Matt Prior told Eurogamer FIFA cross-platform play is something EA Sports has looked into, indeed it's something the developers often talk about, but first-party policy stops it from happening.

"There are a lot of issues to work through," Prior said. "I'm trying to be diplomatic here! There are a lot of issues to work through with various first parties. But Fortnite does that now with PC to consoles. From a consumer standpoint, it makes the community that much broader, which makes it that much more compelling."

Smedley, for his part, encouraged the gaming community to continue to apply pressure on Sony in the hope it'll force a policy change.