Only YOU are making the leap of logic that other amendments gone bad (AGB) demonstrates that therefore, the 19th is bad also. I said twice now there IS NO 'IF THEN THEREFORE' relationship.
The reason I brought up AGB in the first place was to note that just having the amendment process - "they allowed for amendments" - is worthless as a debate point. Amendments can and have been used for good or ill. If my calling out the 16th and 18th as examples of AGB confused you into inferring I meant 'because those are bad, therefore this means the 19A is also bad', that's your problem. And utterly illogical. They stand alone, each as an example of an AGB.
If we applied your standard equally, then we'd still be debating that Representatives (and taxes) should be apportioned according to a formula that counts some persons as three-fifths of a human being.