I don't agree with the whole "it's open source, so if you don't fix it yourself you're just being entitled".
1. We have a finite amount of time each week just like everyone else. Fixing a problem with an open source project might consume a couple weeks of free time just for a tiny bug fix, because of the time it takes to learn a new code base, get tests running, and other administrative details. Larger fixes might consume an entire year.
2. Sometimes, problems are design flaws and can't really be made into pull requests. I have a strong suspicion that some of the problems with NPM fall into this camp, based on my personal experiences with NPM and how badly it performs some of its basic tasks relative to the project's age and maturity.
I'm going to flip this around, so please forgive if this seems trite, but it sounds like you have a sense of entitlement yourself. Users do not "owe" the projects they use pull requests just because it's possible. Users have their own goals and motivations, and if a competing program is simply better than the program you like (from some users' perspective) it's absurd to blame the users for it.
(I mean, from personal experience NPM is an astoundingly poor package manager. I've had it OOM on me on VMs for the most basic of tasks, and some commands are completely unusable.)