I completely agree with Machen & Tullian. If you have a high view of the law (relative to one’s view of man), you want more Gospel because you realize how badly you need it.
However, while I cannot speak to your specific situation, there is at least one more possibility that can lead to parishioners making the kind of confused complaints you recount: a pastor who has a high view of the law but does not preach it accordingly. I raise the possibility precisely because of Machen’s argument. A high view of the law should lead to a greater desire for the Gospel, and yet… they were complaining not just about not enough law, but also about too much Gospel. So could there be a reason the high view was not passed on?
Unfortunately, many pastors with precisely the high view of the law that you describe end up preaching about the law rather than actually preaching the law. For example, they’ll tell their congregation that nobody lives up to the Law but never tell them that God condemns fornication. They’ll tell their congregation that we are all tainted by original sin but never inform wives that God wants them to submit to their husbands. They’ll tell their congregation that none of us love God with our whole hearts or our neighbors as ourselves, but never address the man who doesn’t bother bringing his children up in the discipline and instruction of the Lord. When they do mention specifics, they do so in a shotgun approach intended to cover everyone in the congregation–a mere rhetorical restatement of “everyone’s guilty.” In short: they proclaim their high view of the law without really proclaiming the law itself.
Pastors really need to do both. The law without the proper interpretation just leads to legalism or despair. But the proper interpretation without the law leads to original sin being seen as nothing more than an abstract check mark on some divine spreadsheet. I only recognize the gravity of original sin because I recognize how pervasive is my desire to commit sins. I only recognize the pervasiveness of my sinful nature when I begin to wonder what kind of person would so frequently want to punch someone who is being irritating, or stare at scantily clad women, or play video games instead of fulfilling my vocations, etc. I only wonder such a thing when I am consistently told that such things are sinful–after all, my culture spends a lot of time and effort telling me exactly the opposite. Without specifics from the pulpit, sin just becomes an abstract concept. It’s hard to have a high view of the law and therefore thirst for the Gospel until one recognizes the sin enfleshed in their own lives.
If we simply preached the whole counsel of God instead of trying to game the system by trying to artificially bring about results (e.g. “every sermon’s got to be 49% law & 51% gospel” or “I have 15 mintues to use today’s Bible reading to make everyone feel equally guilty for a second and then make them all stop feeling guilty before I finish”, etc), this wouldn’t be an issue.
Later in the thread, in response to a question about what we then make of the sanctified man and examples of Scripture’s loving exhortation, I also commented:
In my opinion, verses like that have both law and gospel in them. I can still see my sinfulness in falling short of what a sanctified man is supposed to be. They’re also promises of what God will one day make me and is now making me. They remind me that my salvation will one day be enfleshed in a full and abundant life of faithful obedience (which is even now at work) and graciously instruct me on what that looks like. Whether or not they’re “full” of either, they are part of the whole and should be part of the whole that’s preached.
At the end of the day, it’s not the preacher who decides whether we’re restrained, crushed, or graciously instructed by the law–the Holy Spirit does. The preacher’s responsibility is simply to preach the whole counsel of God, including the verses you list. They’re not authorized to restrict their preaching to verses with loving exhortation because they’re more concerned about their flock doing good works (as some missional Lutherans and Evangelicals do). Neither are they authorized to skip or minimize those verses because they’re afraid their flock might become self-righteous after trying and succeeding in doing some good works (as some confessional Lutherans do).