Do you think women should have been able to vote based on the language in 15th amendment?
why was it necessary to amend the constitution by ratifying the 19th amendment?

Based on how the 15th amendment was worded, women would not have been able to vote because it only said that there will be no bias when it comes to "race, color, or previous condition of servitude", which was mainly referring to African-Americans during that time. But more specifically, men. The 19th Amendment paved way to women's right to suffrage because it prohibited any citizen from the United States to not have the right to vote based on gender. 

No we should just pass