Why would you not apply any type of extensions to a severely split nail?

Because you would be damaging the nail even more.





If the nail is frail, brittle and split, you need to let it ';breathe';, by not covering with any glues or artifical nails.





That will inhibit the growth and block light from passing. Your nails will remain yellowish and unhealthy.





It takes months, years to grow nails.. Particularly toe nails, so the more your cover them with chemicals like glue, the less they'll grow.