[clause in simple tense], rather than [verb in -ing form]

Consider the following sentence from wikipedia.

Many people embrace their fetish rather than attempting treatment to rid themselves of it.

When I read it, it flows naturally.But when I analyze it, it seems to me that something is wrong with it. "Rather than" connects heterogeneous forms: people embrace rather than attempting. The logically correct alternative would be:

Many people embrace their fetish rather than attempt treatment to rid themselves of it.

But I can't say if it hits the ear right or wrong.

So... which one, if any is more common/correct/natural?

"Rather than" can be followed by a gerund or a bare infinitive. (There are exceptions when it the two verbs it connects follow another verb that is the main verb of the sentence, but I'll ignore that case for this answer).

To take an example first of something that can't be used with such non-parallel forms:

*People might embrace their fetish or attempting treatment.

People might embrace their fetish or attempt treatment.

People must choose between embracing their fetish or attempting treatment.

Here or does require parallelism between verb tenses, so the first above is incorrect, while the other two are allowed.

Another informative incorrect case is to actually be parallel with a to-infinitive form:

*I would prefer to embrace my fetish rather than to attempt treatment.

I would prefer to embrace my fetish rather than attempt treatment.

Here we have to actually avoid parallel forms.

To come back to your question. In this case we can use both the gerund and the bare infinitive.

In all, either the form you found, or the form you suggest can both be used.

Edit:

It occurs to me that the distinction is hidden by the simple present (when not in third-person singular) and the bare infinitive look the same in English. It could be clearer in the past tense. First a case that does need parallelism:

He embraced his fetish or attempted treatment.

Here we posit two possible actions, that may or may not have taken place at some point in the past. We can even move the subject into what is parallel:

He embraced his fetish or he attempted treatment.

However, it would be wrong to have the same parallelism with rather than:

*He embraced his fetish rather than attempted treatment.

We are not saying that an attempt of treatment was something that happened in the past, or even that it is something that didn't happen in the past (though that is obviously implied), rather we are giving the possibility as one that hypothetically existed when he "embraced his fetish". It isn't something that exists in a moment of time, but adverbally modifies what is saying about the act of embrace, and no more has a tense than would an adverb like gladly, etc.

He embraced his fetish rather than attempt treatment.

He embraced his fetish rather than attempting treatment.

A priori, you might have expected 'symmetry' in the construction, and hence the infinitive after 'rather than'. However, it turns out that the language doesn't adhere to this a priori expectation: there are sometimes elements that have such a strong "affinity" with a particular type of complement that they can override other syntactic associations.

Or to put this in plainer English: 'rather than' (and indeed e.g. 'as well as') strongly tends to be associated with an -ing form, even though if you were to apply some rules of a priori "logic" we're used to in everyday life such as "symmetry", we might have expected a different form.

Another example:

I have to drive three miles to work every day as well as picking the kids up from school.

As it turns out, other languages have similar phenomena. Without going in to all the details, you get a roughly parallel situation in French, where the expressions plutôt que ("rather than"), ainsi que ("as well as") strongly tend to be followed by de before the following infinitive, even in cases where "logically" you would expect de not to be present. If you like, it's case where the "logic" under which the language operates isn't the same "logic" that we consciously expect.