Dear Ravi,
These are generally passive job seekers who attend the interview for the sake of attending without any preparation or planning. It does not happen with active and serious job seekers. One thing more that is noted is that for a single vacancy, HR lines up more candidates than required, and then they run short of time to interview everybody properly. This leaves a bad impression of the company on candidates who have come prepared, making them frustrated. Such mismanagement of the interview process is seen very commonly in companies.
Recruitment processes have to be taken seriously by HR, and only those candidates who have cleared the telephonic round of the interview should be called to save time on both ends. HR can also follow up with the arriving candidates and confirm their timing for the interview, which will help in reducing lateness.
Reena Vashisht