Etiquette advice

[Mctm]

Went out last night for DH birthday. We went to a sushi restaurant in a very middle class town, lots of old money. We ordered LOTS of sushi and weren’t able to eat it all. There was a decent bit left over so asked to take it home with us which they kindly packed up for us with no issues.
As we were walking out I heard a family gasp on a table near the exit, exclaiming ‘they are taking it away!’ (Meaning me & DH as I saw her glance at the box I was carrying). They all gave each other embarrassed looks to each other and then stared at us in a judgemental way making me feel really uncomfortable.

Was I unreasonable for asking for a take away for our leftovers? I understand in Japanese culture it may be considered rude but only the cuisine was Japanese, I could see the chefs in the kitchen and all waiters and they were all white British.
I feel I was met with extreme snobbery from that family and it really upset me or maybe it was a big faux pas from us?

I know it’s not that big of a deal and there are far more important things going on in the world but I’m curious on others perspectives please.

It's not rude. It's a compliment to the chef. You didn't reject their food, or waste it. You appreciated and valued it enough to take it home with you. It is good to be thrifty and better for the planet than food waste, also.

I wouldn't give it any more headspace. You were paying for the food so it was yours to take away if you wished provided that the restaurant could produce a suitable container and/or wrapping.

It isn't rude to want to take home stuff you have bought. To be honest, I am surprised anyone even noticed, let alone commented.

I don't know about you OP, but any 'etiquette' that requires the unnecessary waste of food is irresponsible, outdated and should be ignored by anyone with an ounce of sense. In this day and age, anyone tutting about people acting responsibly to avoid food waste is a fool. However much money they have.

Blimey, I've even had 1 piece of pizza put in a box to take home! More fool them if they're wasting money by chucking away leftovers

That is true! I remember being in America probably 1997 in my 20's in a nice restaurant and the table near us doing it and we were agog and thought it was "common" . And obviously common is the worse thing you can be accused of if you have been brought up by working class parents with a bit of a chip on your shoulder! You need to feel very awkward in a restaurant and not like you have paid for service!

See also eating in the street, women smoking in the street (men ok for some reason), your dress being longer than your coat , men wearing a hat indoors , women ordering at the bar, sitting at the front of the house, and saying thank you to the bus driver (got really bollocked for that one).

The food thing is probably something about cost isn't it - fear of showing people that you are poor and need to use leftovers, bit like when people won't accept handme downs as they think it's a reflection of them being unable to afford new stuff.

I'm not sure I'd take sushi home as I'd be worried about it keeping safely until the next day, but nor would I judge anyone if they did. Maybe they were hoping you'd leave it all so they could swoop in and eat the leftovers??

Were you at Sushimania? They have an all you can eat menu and a normal menu. You cannot take away leftovers if you eat from the all can you eat. That might be what they exclaimed over

I was not at Sushimania, as far as I’m aware there is no all you can eat menu at the restaurant we were at.
I think it’s like what pp said about people who judge someone for walking down the high street eating! So many people do it these days but there are also people who would look down on someone doing that (old money). My best friends grandmother was very posh and would disapprove on seeing someone eating whilst walking down the street thinking it was poor manners and greedy.

In terms of yesterday it was very obvious they were disapproving and judgemental of me taking away food rather than just being curious but I won’t lose sleep over it but it’s interesting to get other people’s thoughts :)

If they used a regular takeaway container then you’ll now it was a reasonable request that they’re happy to accommodate. If they had to stuff it into any old wrapper they could find in the kitchen I’d say it’s probably not the norm

I would enjoy your sushi, and stop worrying what other people think of you.

I wouldn't bother have left over boxed up for takeaway (because I can't be arsed rather than etiquette); however Sushi is the exception. There is no way I would leave decent sushi on the table!!!!!!!!!!!!
So of course you are not being rude

I suspect you misread the family's reaction - even in very upmarket restaurants they are now regularly offering to package up left overs (or don't mind if you ask them to do so).