I also know several open division shooters whom shoot in minor PF. There's certainly nothing wrong with it. If you really want to be competitive in open division, I'm afraid that shooting in major PF is a must. There is of course always a "black swan" that shoots very well competitively in open division minor.
On the other hand, I really think IPSC, and thus too USPSA, really need to review and especially lower the major PF for classic, standard and open division. I do not see a positive reason why it should be that high, especially because of the destructive impact on the guns, as well as the seriously increased cost of reloading nowadays ...