Because how many words do you need for "taco"?
I mean, it's pretty specific, and you can add all sorts of modifiers:
- fish taco
- chicken taco
- beef taco
- taco supreme
So, between the ability of the English language to heavily "overload" words – with prefixes, suffixes, hyphenates and descriptive adjectives – and the inherent self-expression allowed by choosing a unique combination of toppings and condiment sauces, the single word "taco" can express basically every form of platonic, romantic, or carnal love imaginable.
I only speak English, Japanese, and a smattering of French, though – so I really can't say how common it is for there to be multiple root words for this amazing gastronomical treat across the entire globe.