The tattoo doesn't do anything by itself.
So, you just got the tattoo for Draegor's Floating Armaments. Congratulations! Now you must learn what the spell really means. What is the Aristotelian Form of a floating gun? Why does it float? What is its purpose? Getting the tattoo gives you access to the spell, but it doesn't give you the content of the spell, its essence. You must learn that in order to cast it.
As a result, the relative popularity of a spell depends at least partially on its conceptual complexity. If the idea of a spell is simple, it will be easy to learn. For example, it isn't hard to use an Instant Death spell; you just focus on your target, shout "avada kedavra" while really, really wanting them dead, and the target dies in a flash of green light. Easy. On the other hand, a spell like Xanth's Perspective Nullifier would be incredibly difficult. To cast it, the user would have to have an intuitive understanding of space-time, including knowing exactly where they are and exactly where the thing they want to see close-up is. This effectively limits complex spells to savants and highly-trained specialists.
Of course, while conceptually simple spells are easier to learn, that doesn't mean that everyone does, for two reasons.
First, while simple spells are easy to learn, they're also easy to block. You see, while other spells come in a whole bunch of little sub-types due to the different ways people conceptualize them, everybody casts simple spells more or less the same way. This makes them highly standardized, making it easy for people to get passive blocking spells which guard against them and don't require mental effort to operate. Furthermore, most mages have the Metamagic tattoo, which gives them direct control over magic instead of having to use other spells as intermediaries. It gives you an extremely fine-grained control, but at the cost of being very weak. Because of this, it's mostly used for fine-tuning other spells and theoretical applications like devising new ones. In a pinch, it can also be used to modify other people's spells. Usually, this isn't safe to do; randomly messing with somebody else's spell will have unpredictable (but usually very explosive) results. However, for the more standardized simple spells, it's easy for mages to memorize a list of safe modifications to render them ineffective. Since they are easy to foil, most people don't bother using simple spells in offensive applications.
As for civilian use, they're too much of a blunt instrument. For example, while an Instant Death curse would be great for sterilization, trying to use it on a broad area would also kill the neighbor's cat, which would be highly suboptimal.
TL;DR: Spells are either very hard to learn or not very useful, so it's usually easier to just find a mundane way to do it.
