At the end of the day, vegetarians (I am one) would generally prefer to avoid dead animal parts in their products, but it is not strictly necessary to do this - this is one of the differences between being vegetarian (generally speaking, not eating dead animals) and veganism (avoiding any and all animal derived products in every aspect of life). Hence, vegetarians usually don't avoid cow's milk, which is a product with cruelty-to-produce connotations even though no animal death is directly involved. It's this killing of the animal which tends to be the motivation to be vegetarian, and this includes by-products, though most vegetarians will still buy/wear leather, so the whole thing is somewhat confused.
There are, of course, many shades of vegetarianism, and also people who don't call themselves vegetarian but largely avoid certain types of meat (red meat comes to mind), and the tallow/no tallow preference comes down to a person-by-person view on what is acceptable or attractive. I am sure there are numerous vegetarians who use tallow based soap - as they are not following a strict vegan regime.
I don't see that Wickhams is a brand which appeals to vegetarians in particular, but possibly vegans feel it trustworthy. As vegans are so very few in numbers, it makes poor business sense to be the one that serves that market by design, and though I personally won't buy any because I don't think it's nice to smear dead animal on my face (my personal view), Wickhams should absolutely be making tallow based products.
I'm not making any judgement or arguments here, just pointing out facts - each to their own I say.