Why Do Hebrew Speakers Pronounce the Same Word Multiple Ways?

Avi Rockoff writes from Jerusalem:

“My wife and I have just made Aliyah and signed up for Kupat Ḥolim Maccabi [i.e., the Maccabi Health Plan—all Israelis are required to join one of four competing health plans that provide a full range of medical services]. We’ve noticed that it’s pronounced MahKAHbee, as opposed to Judah Maccabee, who is YehuDAH ha-MahkahBEE in Hebrew. I believe that the Maccabi Tel Aviv soccer and basketball teams are also MahKAHbee, and that there is a shift of stress in the names of other teams, too, such as HaPO’el Tel Aviv instead of Hapo’EL. This seems to happen as well with many personal names. Is it the influence on Hebrew of Yiddish?”

Mr. Rockoff is right in his observation. Whereas the formal rules of Hebrew syllabic stress, as indicated by the placement of the cantillation marks in the Masoretic text of the Bible, call for most (though by no means all) nouns and proper names to be emphasized on their final or ultimate syllable, the informal Israeli practice is sometimes to move the stress up to the previous or penultimate syllable. The two pronunciations frequently exist side-by-side, depending on the occasion. MaKAHbi and HaPO’el, for example, might become MakahBEE and Hapo’EL in a ceremony awarding them the Premier League Cup, or even go from one form to the other in the same sentence.