1. There is a vast difference between debating whether children should be taking these medications and whether adults should.
1a. This is true for several reasons. One is the existence and definition of ADHD. A strong case can be made that there is no such thing as ADHD in a qualitative sense, rather, people possess the ability to concentrate in different quantities. If that were true, then society owes it to children to reform the school system and childhood environment to address the needs of more children more regularly. Also, the effects might be significantly different when administered to a non-consenting child with a still-developing brain than when administered to a fully informed and consenting adult with a fully developed brain (and less time, frankly, for long term side effects to develop and present).
2. Regarding adults, I fully agree with OP. The name or existence of your diagnosis makes no difference and you don’t have to justify it to anyone except your doctor and your shadchan. If taking medication allows you to accomplish the things that you need to accomplish, which you would not have otherwise been able to do, then you cannot be criticized for using it. In fact, choosing to use it is in itself a step that you should give yourself credit for.