I understand where you are coming from completely, TCS used to be a low res skin when that was all i had. It all boils down to the difficulty creating low res skins, the reason that the base skins are so sparse is because they need to support every possible resolution, and with making skint that adapt resolution wise you have two options. Adaptable, or lots of information. Making a skin that supports multiple resolutions takes a high degree of skill and especially time, considering skinning isn't a paid hobby and done entirely in people's free time, its understandable why people don't want to commit that time. TCS for example, isn't built to support low resolution screens and even if I wanted to, I physically do not have the time to make a seperate skin.
Another reason is, simply put it's not worth the time or effort that it takes, taking a look at the Steam hardware survey in September of this year which is essentially opt in. Skin makers can focus on the displays that most people have, combined 1080p and 1440p are over 75% of the survey, anything underneath 1080p adds up to 9.53%
Lamenting people for not dedicating hours upon hours to cater to 9.53% of a userbase simply isn't fair in my mind.