She's repeatedly stated that all she wants is fame, she doesn't care how she gets there. The easiest way to achieve fame is through reality television. Not that big of a leap.
You're picking and choosing what to accept as canon and what to disregard just because it doesn't suit your headcanon that Santana has no agency…

Brittany pointed out what she'd have to go through if she wanted to go the reality tv route. Santana didn't like what Brittany was showing her, thus proving that she would't like being a reality tv star.
Santana herself said that her education was not a joke to her. Since she has no direction she tries things,…