Actually, no. A hiring manager is "a manager who is hiring". I.e., not an HR manager, but the person who put in the request to hire someone. Generally their job actually entails delivering a product or service or similar. -Part- of that is filling the team. But that is not what they are measured on. At the end of the day, what they will be evaluated on is delivery, not hiring.

As such, it is up to them how much time they spend hiring, and it is up to them what heuristics they use in that. Because, ultimately, time spent on hiring is time they're not spending actually helping the other team members who they have already hired, and it is only indirectly related to actually delivering the thing they are supposed to deliver (whereas they may have demands on their time that -directly- affect the delivery).

It is also up to you whether or not you try to help them by showing you have actually read the posting, and know something about the company, and whatever other heuristic they have. That's totally your prerogative. But you do not have -any- standing to fault someone whose job is delivering something with not considering you because you didn't want to put in some effort.