Many reasons. Some people like it merely because they think they look cute together due to their personalities, others like it because of the close historical, cultural and political ties between the two countries in real life. In the end, it's merely a matter of opinion. I mean, AmeBela has absolutely NO background to it, in neither the mostra nor in real life (I'm sorry AmeBela fans, but it's the truth) And yet it's very much popular.
For più information on the fangirls' reasons to support the USUK, te can visit this page: link
Eye candy, nothing più and nothing less. People only like it because they find it cute. They take their own country and pair it with their favorite. o just their two preferito characters o two hottest characters. It's just a typical Yaoi pairing, were fangirls use eye caramelle and head canon to ship it. Taking their clearly brotherly moments and making it into Yaoi. But of course, they always use excuses to that, never wanting to admit to them just being brothers.
1. They are cute together and not just in look. America has that personality that fits with England's tsudere-ness. And personality matters people. I mean te can't really expect two oresamas in real life to get along in a lovable relationship. Sure they could but it's rare. 2. The history. Think about it. American history is wrapped around England's little pinky. 3. People like England. People like America. They both fit. Okie-dokie let's put them together. Yep people preference one character and will try their hardest to put the two together.
4. Yeah I don't wanna go into this any further.
~By the way i Amore USUK. But of course I also Amore all the other parings. It's not like its real anyways. Only canon pairing I seen so far is Me X Hetalia.
I will admit, some people like it for headcanons, and fanservice, but what pairing in Hetalia Axis Powers - Incapacitalia doesn't have those fans?
The smart reasons are listed below.
1. There personality's are EXTREMLY compatible. The pair of a tsundere, and a innocent and playful partner works out. Mainly since they complete each other. Whhile a tusndere is normally missing the playful side some have, the innocent and playful type is missing the maturity and sometimes the common sense tsundere's have.
2. Historical reasoning, come on? America and England might've avoided each other for the longest time...but other then Canada, England is one of America's preferito countires (I live here, so don't te DARE say a word about how wrong I am. I have looked up this information) I mean, in history, lot's over look this, but in WWII, we were secertly aiding Britain through the blitz, pissing countries off like France when they learned. Basically, we Lost our neutral status to help Britain. And though they seem like brothers to some people (cough, Fruk fans) some people don't see it that way. So some people look at our history with Britain as a reason to be together
3. It's half way to being canon. Yes...this is a VERY biased reason, but some people fan something because it's one step ahead of everything else. And hima-papa has come out and detto 1. Britain is gay, and 2. he is gay for America. This also helps the non-brother case. Some people may look at this as a sign that England doesn't look at him as a brother, signifying it's not incest.
Please no hate comments, I am a fan that knows both ends of almost every couple in this series, I have Friends who like Usuk, but plenty that like Fruk. For me, I'm half and half, and can find reasons to support both. These are thoughts I can give. I can give some to support Fruk too, but that's not the question.
To conclude, if te want to deny every reason on here, fine. But here's the thing, the first two reasons for one thing are why my sister and I like Usuk. Two, can't speak for anyone else, but I can't STAND fanservice, and any headcanon I've made only deals with one character really. So say what te will, but your wrong if te say I'm chosing sides, o I'm lying.
Respect opinions, respect feelings, and just be happy and get along. Sayoonra~