Think about it more; if the vegan and steak options were ~equivalently priced - more would choose vegan than if it wasn't more expensive. The idea isn't to make it prohibitive; insofaras don't make the most environmentally-expensive choice also the cheapest.
To compare it to traffic; everyone is miserable sitting in traffic; so giving people an excuse for a bit more WFH is a WinWin.
As a committed meat-eater: I have no idea what vegan food costs, as the label almost immediate makes me skip over them. To make me look at them, you'd have to make the non-vegan options prohibitively expensive.
> more would choose vegan than if it wasn't more expensive.
If?
Getting protein from vegan sources can already be done much more cheaply than getting it from steak, though the quality of the amino acid profile may be lower.
Getting protein from "the vegan option to a steak" - i.e. something marketed to be a direct substitute for a steak, with its vegan nature as an explicit selling point - is a different story.
I presume that, generally, people eat steak because they subjectively enjoy the experience of eating steak, and perhaps because they don't enjoy a carefully planned out plate of legumes and whole grains in the same way. But some seem to be much more extreme about this than others.
I personally eat meat (and dairy) regularly - but probably overall less than the local average, and usually not beef.