Complex sentence: Others point out that they are the most natural gender-neutral pronouns, and easy to learn, since they derive from an already well-known form, and are therefore preferable at least to the sie/ze/zie/xe forms.
Split into simpler sentences: Others point out that they are the most natural gender-neutral pronouns and easy to learn, since they derive from an already well-known form. Supporters feel that this makes them preferable at least to the sie/ze/zie/xe forms.