Think the biggest issue is the difference in refereeing when fouls happen inside or outside the box. If any player, between the two penalty areas, goes on a run and gets pulled by his arm or touched on his shoulder like Salah was, the vast majority of the time the referee will blow his whistle even if the player doesn't go down. Most of the time the player committing the foul will receive a yellow. We'll usually call it a 'professional foul' or 'taking one for the team'.
If Salah stays on his feet there, we're not getting a penalty. Simple as that. If it had happened in midfield with him staying on his feet and perhaps throwing his arms up, we'd get the foul.
The biggest issue really is the inconsistency from referees rather than Salah making a meal of it. If referees would actually reward players by giving penalties when they are fouled but do (try to) stay on their feet, like Salah's goal against Bournemouth, players wouldn't feel the need to go down in order to get the penalty they do deserve. Players go down because they feel that the only way to get a penalty, is to go down, even if there's minimal contact that might cause them to be off-balance.
I don't like Salah going down like that at all and it was a soft arse penalty, one I'd be fuming at if given against us. Won't blame him for doing it though. It's the F.A and the referees that need to get their heads straight.