Personally, I think that calling this pet store "evil" is a little far-fetched. Yes, it's upsetting that they're mixing species, but you have to remember that almost all pet stores only keep animals long enough to sell them, and are often quite misinformed on proper husbandry. In reality, most pet stores do that sort of thing all the time and a lot of people often create threads complaining about them. Though there are a few people who "rescue" these animals (who are generally under a lot of stress from importation/being in the wrong environment,) they create higher demand for these animals, so it creates a vicious cycle. The pet store turns profit on an animal, then buys/imports more to satiate the demand.
It takes up less space to house all of the amphibians together, to make room for more merchandise (ie: other animals,) than to house them correctly. With few exceptions, pet stores do not know/care for the animals they sell. They're only looking to turn profit.
Time and again, people ask on the forum questions regarding their animal's welfare, having been told something completely different by a pet store clerk.
For instance, not only are they housing Firebellied Toads with Axolotls, but they've also mislabeled what looks to be Paramesotriton as "Firebellied Newts" (Cynops orientalis.)
Also, not only is this pet store located in England, (if any of the British patrons of this forum want to stop by and complain, that's fine,) but the page hasn't been updated since January, so who knows if those animals are still there, still housed together or still alive.
Personally, I think the lynch-mob mentality that people take against pet stores is somewhat silly. Most pet stores are just like other retail stores - they sell merchandise to appease public demand. Their main priority is to turn profit and will do so regardless of the toll it takes on the animals. They hire apathetic and/or uneducated employees, who can/will/are taught to tell a prospective customer what they want to hear to make the sale.
I'm not saying all pet stores are like this, but a lot of the chain stores are. There are definitely good ones out there, and once you find them, don't go anywhere else, but a lot of them aren't.
Just my .02 cents.