That said, I feel there are a lot commenting, not so much against the hunting, but more to do with what they perceive as a 'class' resentment. That these people are able to do what I can't do, they've perhaps had a better education than me, or live in a bigger house, drive a better car, so I have a hate for them.
I mean the League Against Cruel Sports was first set up by one bloke who went to Eton and Cambridge and another that went to Cambridge (in the 1800s, where they presumably didn't have diversity quotas for povvos), so let's not pretend it's only class envy that causes this. But yes, there's definitely a class element in popular culture, and that's because it's seen as another example of 'one rule for them.'
When the Cruelty to Animals Act was first introduced in 1835, dog fighting, cock fighting and bear baiting were banned (along with various general cruelties to working animals a livestock). There was no distinction made there between upper class and working class cruelty. Dog fighting was very much a working class thing, whereas cock fighting was an upper class thing. And even in the 1911 legislation, hunting was clearly seen as a completely different thing, with not much thought to the methods. Although it's worth mentioning that it did include rules about how often you had to check traps to avoid animals having a slow, painful death, so there was some idea that even hunting had to be done 'humanely'.
I think since then, and even at the time for some, people have perceived a smaller and smaller difference between the sort of baiting, fighting 'sports' of the 19th century, and a bunch of people going for a jolly day out on a horse while killing an animal. In both cases, the main aim is entertainment. People have the same issues with the shooting of effectively captive animals, where places breed animals just for people to shoot. We saw the same outrage about Cecil the lion in Zimbabwe, or similar places in South Africa, where ordinary, middle-class people are typically the people doing the killing (Cecil the lion was killed by a dentist, not a duke). Or bullfighting in Spain, which seems to be popular among the masses.
To the extent to which it became a class issue, you have to ask yourself how much of the blame falls on the House of Lords. This is a house that is massively overrepresented with members of the aristocracy and upper classes, who repeatedly refused to pass the will of the democratically elected house. You can't help but think had the legislation been about any form of animal cruelty other than the one that happens to be enjoyed by many upper class people, it would have got through at first reading.