So you have one change that will slowly fade away, while the other is a fixed, measurable, and comparatively immutable change. As the officials stop calling as many penalties, it's not like you will see the length of time that teams are on the PK decline in a graduated manner to match it. Any quick change again to two minutes would be an admission they screwed up, so it would be years before they could save face and go back to two minutes for a minor.
So you'll have fewer and fewer minors called, but they'll all still only be for one minute apiece. The result is that you'll get fewer goals. Some may be fine with that, but the league generally wants to encourage scoring.
I think the argument here is something like this:
Currently the average NHL game includes something in the order of 3 power plays for 5 minutes of PP time per team. We can generalize by saying that means 3 minor penalties, one of which is cut short by the other team taking a penalty.
Now I’m going to totally make up some numbers here, but — let’s say this change is designed to create a 50% increase in the number of penalties called. Of the new total, let’s say 60% of the penalties being called are of the “not serious” variety which are now 1-minute minors. That would mean something like 5 penalties for 7 minutes of PP time on average. Bear in mind we are talking about an average over a large sample, so this number would start out higher before settling into the 5PP/7min norm.
Based on these averages, what we’d be seeing on a practical level would be the equivalent of one more PP per game for each team. That’s not a radical departure from the current norm… it would result in roughly one extra goal per 2 games played (or one per team every 4 games). That’s enough to move the needle on GAA and total scoring, but not by much.
The more important thing is that according to these assumed numbers, we’d be seeing something like 3 penalties per team for small hooks, holds, etc
in addition to more serious fouls like high sticking. That rise in enforcement against the minor stuff (what we currently view as ticky-tack calls) would drive a general shift to a more fluid standard of play. It’s not the PP scoring that sells this idea — it’s the fact that players could count on going to the box for that little crosscheck or hook that officials are currently hesitant to call.
The permanent impacts of that kind of shift can be profound. Power plays are
way down from 2006, because officials no longer hold as strict of a line against obstruction fouls as they did back then. But the general pace of play has remained much faster since the obstruction crackdown, because it led to a fundamental shift in how rosters were built. Even in the worst morass of a no-whistles playoff gladiator brawl, we never see anything approaching Dead Puck hockey. That traces back to a relatively brief period where the officials felt empowered to alter the course of a game based on a relatively trivial offense — that empowerment and resultant shift in strategic dynamics is what this change would be designed to not only induce temporarily, but institutionalize permanently.