It's quite the leap of logic to suggest that a few words you see as meaningless are capable of undermining any point a poster is trying to make. Surely it would have to have meaning contrary to the original point in order to undermine it. A more accurate description, I'd wager, is that your pet hate of the phrase causes you to disregard the point made by the poster. It's understandable, some can use it to mask really shallow thinking, but it means you automatically discard a potentially good point.
The phrase "PL proven" can be used to summarise the fact that the PL requires a much higher technical level than almost every other league in the world, on a par with the other couple of top leagues around Europe, and that the level of physicality is arguably the highest of any league. There's also the pressure, with the media spotlight being extremely bright, with tabloids eager to find their next laughing stock. Given how difficult it can be for players to adjust to the league, removing that variable is a big plus for prospective signings.