That's your interpretation.
You're reading it saying "A bishop MUST be married to one woman". I read it as "IF a bishop is married he must not be married to more than one woman"
Except the Scripture doesn't say "IF a bishop is married"
It says
"IF a man desires the position of a bishop, he desires a good work. A bishop then MUST be
-blameless,
-the husband of one wife,
-temperate,
-sober-minded,
-of good behavior,
-hospitable,
-able to teach;
-not given to wine,
-not violent,
-not greedy for money,
-but gentle,
-not quarrelsome,
-not covetous;
-one who rules his own house well, having his children in submission with all reverence (for if a man does not know how to rule his own house, how will he take care o the church of God?)
-not a novice, less being puffed up with pride he falls into the same condemnation as the devil.
-Moreover he must have a good testimony among those who are outside, less he fall into reproach and the snare of the devil.
Do you want to know the difference between my interpretation and yours?
You make the claim that the person is a bishop first and then some of the qualifications can apply. For example when you said "
IF a bishop is married he must not be married to more than one woman", you inferred that one can be a bishop but they do not need to meet all the qualifications. My interpretation says that if one does not meet the qualifications--and those qualifications are a must--they should not be a bishop. The position of a bishop is NOT given to the man and then they meet the qualifications, the position of a bishop is something to be desired and then if they meet the qualifications they should be bishops.
I'm getting the feeling that someone is going to say that "must" only applies to the qualification of "blameless" but I implore you to read it again because Titus 1:5-9 re-illiterate many of those same qualifications.
If this helps, I'll quote Titus 1:7-9
5 For this reason I left you in Crete, that you should set in order the things that are lacking, and appoint elders in every city as I commanded you— 6 if a man is blameless, the husband of one wife, having faithful children not accused of dissipation or insubordination. 7 For a bishop must be blameless, as a steward of God, not self-willed, not quick-tempered, not given to wine, not violent, not greedy for money, 8 but hospitable, a lover of what is good, sober-minded, just, holy, self-controlled, 9 holding fast the faithful word as he has been taught, that he may be able, by sound doctrine, both to exhort and convict those who contradict.
A man must be these things if he wants to be a Bishop.