Often times we forget that Spot, like every other company exist purely to make a profit. They answer to the investors, not their employees. Corporate conscious and responsibilities are often times neglected. And as such, from a business perspective its understandable management would try to cut cost, with labor being one of the prime numbers, especially in mature companies such as Spot.
One can argue that paying a better wage to those working at the lower levels would lead to better moral, services and in general a much more friendlier environment which in the long run would boost sales and revenue/profits, but then we have to consider factors that really pushes against it. First, its the investors again; increasing wages, benefits and all that good stuff would stick out on any earnings report while the boost in sales/revenues/profits take time to manifest. Investors aren't known to be the most patient, and it'll be hard to convince them otherwise without the stock of spot taking a major hit and affecting a sizable dividend that Spot pays out.
The perception of retail work is another wind hard to sail against, because the prevailing argument is that retail work should only serve as a temporary job, transition job or a supplementary job. As such, a company cannot commit too much resources to a workforce that is expected to have high turn-over, that wouldn't be efficient and very costly.
I'm sure there are other reasons, but its just my two-cents on the whole hours, benefits and pay stuff. Do I believe they can afford to pay more, even though its retail? Absolutely, companies like Costco pays very well across the boards for their employees, but unfortunately Spot operates differently, and Spot's investors have their own expectations/agenda on how the company should be operated and how their capital should be invested.