1) Many range rental guns are rarely cleaned. And they are abused like a rental car. Bad cleaning practices in ANY gun can cause striker issues. Over lubrication can cause striker issues. This was most likely the issue.
2) The one weakness to the M&P IS the striker. They have a tendancy to break strikers with lots of dry fire. Range rentals find their way to the case after hundreds of customers have "tested" them. Then see above... Dry-fire with snap-caps helps, and most of the newer M&Ps have improved strikers in them, but likely this is an older model, and abused, and cleaned poorly if at all, and/or over oiled, causing grit to build up in the striker channel... Soft-strikes... No boom.
Your ruger is striking the primers correctly... Don't blame the ammo, or the M&P... Blame the knuckleheads who get paid NOT to clean it correctly.