It's fairly rare that an
issue of landlord/tenant law climbs all the way to the top state court. There are a few reasons for this, or at least a few that I can speculate are reasons from my own practice. One of the biggest is probably "mootness." By the time a case crawls slowly toward the top of the heap, the facts of the situation have changed. If a person has moved from a building, or it has burnt down, etc., the right of the person to claim possession no longer really is a legal issue. A court isn't going to waste time to decide something when the decision really won't have an effect on the parties.
Second, appeals are generally time consuming and expensive. Point 2(a) would then be that, in most eviction situations, neither party is fabulously wealthy and able to spend thousands of dollars to fight about a few hundred in rent. Point 2(b) is that, in most ll/t situations, there's an extra layer of appeal before the top court and taking it to the top is extra-lengthy and costly. Evictions are heard, usually, in the justice courts and city courts. Appeals from these courts go first to county court. Appeals from county court go to the Appellate Division. Appeals from the AD go to the Court of Appeals in Albany. This is different than the "normal" (if anything can ever said to be, of course, but speaking mainly of the way we learn it in civics classes and poli sci) procedure where a case goes from county/Supreme to AD to CoA.
Third, tying into 2(a), is the involvement of stakeholder groups. Cases out of eviction court rarely go all the way to the top unless various groups see that the decision will have an overarching effect. Some wealthy landlord corporations are probably willing to litigate the issue to the end, since it will impact on hundreds or thousands of units. The tenant side is, most often, represented by legal services-type offices. Very few people who can afford a private attorney end up in eviction court under normal circumstances. Such offices are restricted in the cases they can take on appeal, due to limited funds and resources. Additionally, and actually the third point I wanted to make as it concerns both sides, is the concern of binding precedent. The higher the court, the larger the area of the state that is bound by the decision. There's always a risk when one appeals. A decision you're not happy with could be tossed, but it could also be upheld, or in some cases, made even worse (from your POV). From conversations with many lawyers in WNY, it seems that sometimes, taking a long view, it's easier to swallow a bad decision and move to the next fight than push the issue and end up having all cases decided in the "bad" way by operation of law.
The recent decision, as reported by the NY Times in brief, is one of the rare ones that fills all the necessary holes. It is a major issue that has appeal to both ll/t stakeholder groups as something that needs to be settled by a court, justifying the time and expense because of the sheer importance of the issue.