What is your opinion on names such as "Saleh," "Ali," "Maryam" (meaning "worshipper"), and "Sa'd," knowing that they carry commendation or may evoke pessimism, and that you have disliked names like "Iman," "Islam," and "Rahmah" for the same reasons?

It is disliked to name children with names that imply تزكية (self-praise/purification) or might cause pessimism. The Prophetic Sunnah has stipulated this, and the Prophet, peace be upon him, changed some names like "Barrah" to "Zainab" or "Juwayriyah" to avoid تزكية or pessimism. The dislike of these names is a dislike of tanzih (dislike of an action, but not to the extent of being haram), not tahrim (prohibition). The Prophet, peace be upon him, forbade naming children "Yasar," "Rabah," "Nujayh," and "Aflah" due to the pessimism that might result from a negative answer (e.g., if asked, "Is Yasar [Ease] there?" and the answer is "No," it might imply no ease).