While it may be true that some employers use deceptive tactics, the overwhelming majority do not. It is not in the interest of the employer to scare away jobseekers by specifying false requirements. When an employer doesn't find the person with the minimum qualifications, more often than not they will extend the application deadline, re-evaluate the compensation to increase their chances of finding the right person, or just not fill the position.
Overqualified and under qualified people are not what they employer wants because inevitably problems arise that cost time and money. Overqualified people require more pay, are more likely to leave when a better job turns up, so that the employer has to fill the job again. Under qualified people can take too long to do certain tasks, or can make costly mistakes. Candidates within a narrow range of qualifications are usually who employers are willing to consider.
However, there are situations when it would be a good idea to apply for a job that you aren't exactly qualified for. If the posting says "equivalencies considered" or "salary under review", chances are good that they are really keen on filling the position and are having problems either because the market is weak or their budget doesn't allow for appropriate compensation. In either case, they will probably wind up taking someone different from their initial plans. But for the most part,the maximal strategy is to search only for those positions for which you would be a reasonable fit, to find as many as you have time for, and then to apply these companies.