The additional pressure allowed in "Ruger only" loads does not only allow greater velocity. It allows far greater bullet weights and that is where the .45 (and all other magnum revolver cartridges) excels. Yes, standard pressure loads are potent but they are limited. A 270-280gr bullet is about all you can get to a meaningful velocity. That velocity does serve a purpose. For a 1200-1300fps load is much easier to stretch to 100yds than a 900fps load.
The .45Colt loaded to 32,000psi is equal to the .44Mag, it does not exceed its potential. Both cartridges can utilize the same weight bullets, right up to the maximum practical weight of 350-360gr. The .44 may enjoy a slight but irrelevant velocity advantage.
The .45 is not universally "bigger" than the .44. The overall bullet diameter is meaningless. The operative dimension is the meplat diameter, as that is what creates the wound channel. As such, sometimes it's bigger, sometimes it isn't.
In my penetration testing, the .44 was decidedly the better penetrator.
What a man hunts with is his own choice but the notion that a properly loaded big bore revolver is inadequate for big game is patently false. Perhaps your own handgun skill is not up to the task but do not judge others by your own shortcomings.