Argument #1 : They're both guys.
So? So were Zoicite and Malchite from Sailor Moon; Nuriko and Tomo from Fushigi Yuugi, etc... Homosexuality and bisexuality are not looked down upon in Japanese culture, as part of the whole, "don't ask, don't tell" philosophy. All forms of sexuality and other ways of life are accepted as long as they are practiced in the privacy of one's home and/or in socially acceptable situations, such as nightclubs.
Argument #2 : Tai is meant for Sora, and Matt is meant for Mimi.
Lack of creativity too great....must get help...must write more imaginative fanfiction... Okay, although Taiora pairing is by far the most popular of all digimon pairings, I really must disagree with the entire thing. I mean, the whole 'male lead is destined to fall in love with female lead' thing totally turns me off! It follows that old pattern so closely! You can practically tell where a story is going before you read it! Really. Kill me now, God, lest I die of boredom first. As for Mimato pairing, am I the only one who ever notices that Mimi and Matt hardly ever interact?! There is absolutely nothing to base a relationship upon! Besides, I think Mimi would be cute with Koushiro, or maybe Jyou... ^_^
Argument #3 : Tai and Matt are just friends.
Yes. At age 11. They ARE going to mature, you know. The two talk together, plan together, Matt's cried in front of Tai, Matt HELD TAI'S HAND in one episode for chrissakes (I forget which one it was, it was right after they discovered Kari was a digidestined. Matt and Tai had to be shot with arrows from Angemon and Angewomon; Matt took Tai's hand in his, saying he was making sure Tai wouldn't get scared and run off. ^_^ Sure Matt, we believe you!) It's perfectly believable that they, being so close and well suited to each other, would develop funny feelings later on.
Argument #4 : Tai and Matt can hardly stand each other, let alone love each other!
This argument is surprisingly popular, despite the fact it totally contradicts agrument #3. Yes, they can hardly stand each other. Tai is a leader, and Matt is a rebel. They are always at each other's throats, sometimes literally, and neither of the two ever seems to be hesitant for a chance to hit the other. But they are very close friends, deep down, and that's the very reason they beat on one another. Think back to elementary school. Do you remember the clumsy way everyone would flirt back then, and even through on to high school? Hmmm? THEY PICKED ON EACH OTHER!!! Matt and Tai express their love in awkward, playful ways, much like an elementary student who is inexperienced in love. Besides, opposites seem to attract, ne?
Argument #5 : Digimon is only a kids show, and even if homosexuality is accepted in Japan, such a relationship would not be appropriate for small children.
Neither is a male/female relationship, my friend. They'll be learning about 'the birds and the bees' soon enough, you might as well tell them of 'the bees and the bees' too, since it IS a part of every day life in today's world.
Argument #6 : It is morally and physically wrong!! You shall rot in Hell for all eternity for even THINKING such a thing!!!!
You scare me.