Why do people consider shias to be kafirs??????????????????????????? Please fill me in is it because of tawassal??????

The evidence for tawassul through the awliya' or saints is also abundant, and it suffices that Allah strictly warns all believers to keep company with them when He says: "O believers! Be wary of Allah, and keep company with the truthful!" (9:119) and He enjoins the followership of those who have turned to Him in true and complete repentence (31:15). The Prophet said to al-Firasi, concerning asking from
If you absolutely must ask from people, then ask from the righteous ones"


is it because of propaganda? can i have some quotes from the Quran?
people: "

Please shed some light