The objection
"Animal advocates can make their arguments, but they can't force their lifestyle on others through laws. Everyone should choose for themselves."
Problem 1: it's speciesist
People who say this accept laws that protect humans. Nobody says that banning the murder of people is "forcing a lifestyle" on anyone. If the victims were human, this objection would be rejected right away. It's only accepted because the victims are animals.
Problem 2: it contradicts itself
The objection defends a right: the right not to have things forced on you. But at the same time, it says people can force anything they want on animals, including extreme suffering and death.
The real lifestyle being forced on anyone is the one forced on exploited animals, who have no choice at all.
The extreme version
Sometimes the objection goes even further: "Just by arguing against exploitation, you're already forcing your lifestyle on others." That's even more arbitrary. Arguing means offering reasons for the other person to think about; it's the opposite of forcing.
If someone said that criticizing violence against people is "forcing a lifestyle," everyone would see that's dishonest.
In short
- Nobody calls laws that protect humans "forcing something on people."
- The objection defends not having things forced on you, but accepts forcing suffering on animals.
- Arguing isn't forcing; it's giving reasons.