YABU. It's not really any of your business if couples want to do most stuff together, and I find it weird that you - or anyone else - is bothered by it. My DH is my best friend; I know some people find that weird/sad/cheesy etc, but quite honestly I don't care. In my experience, the people who are most judgy about this, are just jealous, and a bit bitter that they don't have the same kind of relationship. They won't admit they are, because they don't realise they are, but they are......
Like a few people, I know some couples who work 9 to 5 Monday to Friday, and do individual hobby groups a couple of evenings a week, and go to the gym or badminton etc with their own individual mates (and not each other.) Then he spends all day Saturday at footie or golf, and she goes to her mum's or out with her friends (or the kids if they have any.)
I think that is WAY more odd and strange than couples who do loads of stuff/most things together.
That said, I would never take my husband along when I arrange to meet a friend for coffee or lunch (or expect her to bring her husband.) And I would not go along with him when he is meeting a mate for a drink. That's a bit weird.
Also, I think sharing a facebook page is beyond bizarre. I also do the food shopping and bill paying alone whilst DH is at work, as he works longer hours than me, and I have more free time.
I do often go out with DH when he goes to the doctor, (and he sometimes comes out when I go,) but it's because we live 5 miles from the surgery, and it's in the centre of town, (where all the shops and everything is.) So we go together and kill 3 or 4 birds with one stone - pay a bill or two, get some milk and bread, do any banking we need to do, go to the post office etc etc...
I don't go in with him to actually see the doctor however, and he doesn't come in with me. He does like me to accompany him to hospital and clinic appointments because he gets anxious on his own. I prefer to go to such things alone though.
But yes, we do do quite a lot of stuff as a couple. And we always go on holiday together/on day trips together. We are a happily married couple of almost 30 years, who are very much in love, and care deeply for one another. Why wouldn't we? 