Tomas Liutkus lays out the case against bringing Montenegro into NATO:

It’s key to remember, however, that NATO helped the Baltics progress along paths they had already started walking. The alliance did not create viable, democratic systems of governance where none existed — nor could it have. Yet that seems to be exactly what NATO is attempting to do with Montenegro.

NATO stands to gain nothing by admitting a country whose citizens are largely indifferent to membership and whose government remains deeply dysfunctional [bold mine-DL]. It would be better for the internal stability of both NATO and Podgorica to wait this one out, push Montenegro to institute much-needed internal reforms, and then revisit expansion when the country is truly ready for it.

This is very well-put, and I agree that NATO shouldn’t take Montenegro in. I would just add that Montenegro isn’t going to add much of anything to the alliance later on even if its government has reformed. Alliance membership has too often been dangled in front of potential members as an incentive to get them to pursue political reforms, but that isn’t what a military alliance is supposed to be for. If it has a reason to exist at all, the alliance exists to enhance the security of its members. Adding another member that isn’t going to pull its weight doesn’t make sense even if it has a fully liberal and democratic government. However, as Liutkus makes clear, Montenegro doesn’t even have that at the moment.

Liutkus makes a good point that indulging Montenegro’s current government with membership despite its serious flaws has another downside:

Djukanovic has long based his legitimacy on his purported support for European integration and NATO membership, while demonizing the opposition as Russian proxies. In reality, the vast gap between Djukanovic’s pro-Western rhetoric and his own corrupt record has only increased Montenegrins’ cynicism toward Western institutions.

Integrating more states into Western institutions has often been justified as a means to promote democratic reform, but in this case bringing in Montenegro seems to have become an end in itself. If most people in Montenegro were enthusiastically demanding such integration, that might make a certain amount of sense, but when there is no consensus in favor of joining the alliance it is a bad idea for both NATO and Montenegro.