Los placeholders causan problemas

El uso de los placeholders causa muchos problemas, no solo de accesibilidad, también de usabilidad. En Placeholders are problematic, se explican muchos de los problemas:

Since the placeholder attribute came along, lots of us started using it as way to show form field hints. Their appeal lies in their minimal aesthetic and that they save space. 

Some go a step further replacing labels with placeholders. Either way, placeholders are an inclusive design anti-pattern.