They only truly become homosexual if they act upon any same sex attraction feelings they may have. This word homosexual is a loaded word. People go through stages in how they feel and are attracted to others as they mature. If these feelings or attractions are acted on in the wrong way then it reinforces feelings which may or may not be appropriate. In the case of Same Sex attractions the Church teaches it is wrong and sinful to act out. Some people with these feelings may have better control then others or they may be stronger, the feelings stronger in one then another. The problem we have in today’s culture is these false ideas that if it feels good then do it. This is the trap many that have same-sex attraction fall in to.
They do not want think there is anything wrong with certain feelings, and of course none of us want to think there is something wrong about our feelings, emotions, character or etc. but each of us have parts of us that want to do the wrong thing, but all of us should strive to be the best we can.
In this argument of Homosexuality the majority of the people which do not want to recognize, IMHO, that there is something wrong with these disordered sexual feelings will, as any that are in denial of any disordered behavioral tendencies, want to beat the Church down and the rest of society with any every excuse that they are right and the Church is wrong. This truly a sign of immaturity, which many think, is the root of homosexual tendencies that is something went wrong in the process of individuals growing from childhood into adulthood. That is not say there are not intelligent, well meaning, and creative - even highly (worldly) successful persons that struggle with same sex attraction, in fact it appears that the more educated one is the more likely they may have problems with same-sex attractions. Go figure, maybe the tree of knowledge is truly evil