[vezzy-fnord]

In very broad terms, this is part of an age-old debate in the philosophy of science about how mathematics should be interpreted - instrumentalists (manipulating symbols) versus realists (mathematics underpins objective reality).

Realism is obviously popular because any viewpoint which attaches grandiose "meaning" and "purpose" to things is bound to be more popular over what is seen as "colder" and analytic.

There's actually several sides, but those two are the main ones.

EDIT:

In addition,

For a creator God, we are left to ask who created the creator - but if the universe is a mathematical object, it needs no creator (on Platonism at least), so this is a very satisfying answer to that eternal question. It has always existed and will always exist outside of space-time as a mathematical construct.

No. In fact, a lot of people who subscribe to creationism make the exact same argument - that God has always existed outside of space-time and requires no creator. Your handwaving this in the same fashion is not a satisfying answer in the slightest.