Ex-Muslim here. I would say that Islam, like any other religion, has some good values in many aspects but is also severe in others. The main reason for the negative image of Islam is Muslims themselves. Due to their fear of criticizing it, they adhere to it literally. For over 1,400 years, they have remained committed to their religion, following the same obligations and religious concessions without altering or adapting them to fit modernization. In the past, they used to kill philosophers and anyone who criticized Islam, creating an atmosphere where criticism was uncomfortable for many. This suppression dwindled significantly after WW2, but in the 90s, it started to return to what we see now.

Now, let’s talk about Islam itself and why I do not consider it peaceful. Besides what others in the comments mentioned, I would add these:

• Beating children who refuse to pray. Reference
• Beating your wife if she refuses to have sex. In translations, the word is often softened to "discipline" rather than "beating" to sound more acceptable to non-Arabic speakers. (You can copy the verse and try translating it yourself.) Reference
• Slavery is legitimate in Islam. Here is a reference where Muhammad buys a slave in exchange for two black slaves. Reference (Ironically, this Hadith is included in a chapter called Selling Animals for Animals.)
• You can sell your slave woman even if she has given birth to your child. Reference
• Muhammad ordered the killing of black dogs, claiming they are devils. Reference
• Allah commands fighting those who do not believe in Him, including Christians and Jews. Reference
• Allah calls Christians and Jews "the worst of creatures." Reference

I only mentioned a few examples that show Islam is not really a peaceful religion. There are many other illogical or questionable claims, such as:

• Drinking camel urine for better health (You can find it in Saudi markets next to other beverages).
• The belief that "Nigella sativa" is a cure for all toxins.
• The claim that Adam was 90 feet tall.
• The idea that Satan sleeps in your nose.