I have no interest in same sex marriage for my tamagotchi, either. If anything, I kind of enjoy the parameters set by the gender. Japan isn’t the west. They have a different set of rules and some things aren’t as important there as they maybe in other societies. No matter the current year, Japan is Japan. It’ll always march to the beat of a different drummer and the tamagotchi is a product of that. We should also remember that these toys aren’t made for western adults, but young Japanese girls. There’s no obligation for Bandai to do anything different from what they’ve already been doing, as it’s been successful for their target audience.
While gender wasn’t a thing back in the day, the whole ‘marry them to get rare Tama genetics’ wasn’t a thing either (and I kinda miss the ‘weight’ category). Since new Tamas are hatched from eggs, I’d say they’re closer to animals. There’s also the words used for both genders/sexes. In the M!x, it says めす for girls and おす for boys. Both terms are identifiers for gender/sex but they’re exclusively used for animals. They only exist within the world of Tamagotchi and that means there isn’t a need to change anything about how they already function, since it’s not mimicking any particular values or beliefs of our society.
Adding something like this could create problems in terms of what Bandai decides to include and what they don't. For example, if they were to include the same sex marriage function, something that would cater to a minority of their user base, what would happen if someone wanted to have their race represented? While they aren’t humans, there are characters like Santaclautchi who have a distinctly human appearance. Something like this could force Bandai to take a position on certain issues (i.e. morals and politics) that Japanese companies usually try to stay away from. I applaud those companies for remaining neutral as it causes less conflict. Not including something is different than speaking out against it and does not harm anyone or their feelings.
The idea of ‘if you don’t like a feature, you don’t have to use it’ could also be applied in the reverse. If you want your tamagotchi to be able to marry the same gender/sex but that isn’t available, you don’t have to buy or use them. If the west is anything to go by, the option for same sex marriage won’t just be available, it’ll be advertised as the only worthwhile feature in that iteration. This could definitely alienate people who don’t agree with that lifestyle choice and it’s still a point of contention for many. Japan is a society that puts emphasis on the group, not the individual.
I don’t usually care about stuff like this but I don’t think it’s right to compare apples to oranges. The U.S., as an example, and Japan should never be compared on stuff like this because they’re two completely different countries. Both have their own set of values, history, morals, politics and ways of operation. Just because one country does X doesn’t mean all other countries should follow along. Values and such are all subjective. If I were born in a different country, many things I believe would probably be different but that wouldn’t make my current values either right or wrong. If you want it fine, if you don’t fine. I just don’t think it’s fair to paint a company in a negative light because they don’t add a feature to a children’s game. Enjoy it for what it is. However, this is just my opinion ¯\_(ツ)_/¯