Treat Wikipedia as you would any other popular reference source. There have been several studies published on the reliability (or otherwise) of Wikipedia. I listed a few in my answer to a related question here, but I have no doubt that a quick Google search will find plenty of others (other search engines are available).
However, just as with any popular reference source, you should always check the citations where possible.
In this case, the person posting the comment was correct when they said that your suggested etymology isn't supported by Wikipedia. What the article actually states is:
The origin of the term is unknown. According to etymologist Anatoly Liberman, the only certain detail about its origin is the word was first noticed in American English circa 1890.
citing Anatoly Liberman's article, On Hobos, Hautboys, and Other Beaus on the OUP Blog as its source.
Now, you are correct that the Etymology section of the Wikipedia article goes on to observe that:
Author Todd DePastino has suggested it may be derived from the term hoe-boy meaning "farmhand", or a greeting such as Ho, boy.
This time the cited source was An interview with Todd DePastino, author of Citizen Hobo: How a Century of Homelessness Shaped America. The interview is published on the University of Chicago Press website.
In the interview, DePastino said:
Where did the word "hobo" come from? I've not found a convincing explanation. Some say it derives from the term "hoe-boy," meaning farm hand, or "homo bonus," meaning "good man." Others speculate that men shouted "Ho, Boy!" to each other on the road. One particularly literate wayfarer insisted the term came from the French "haut beau." Whatever its origin, the word "hobo" became widespread in American vernacular during yet another major depression from 1893 to 1897.
So, was the Wikipedia editor right to say that:
"... Todd DePastino has suggested it may be derived from the term hoe-boy ..."?
Well, perhaps. But in that case, the emphasis in that sentence should be heavily on "may" and it really is stretching the point.
Personally, I would say it is certainly not an accurate representation of what DePastino actually said.
It would probably be more accurate to state something like:
"Author Todd DePastino notes that some have said that it derives from the term "hoe-boy", meaning "farmhand", or a greeting such as "Ho, boy", but that he does not find these to be convincing explanations".
Leaving the citation link to the interview unchanged. (If anyone feels inclined to improve Wikipedia at this stage, feel free to use that text).
The point here is that - as with any popular reference source - the reliability of Wikipedia depends both on the accuracy of the sources cited, and the skills of the editors who collaborate to produce the articles.
In this case, had you checked the cited source, you might not have been quite so emphatic when you defined 'hobo' in your answer.
Equally, had the commenter taken a moment to check the source, they might not have been quite so quick to cast aspersions on Todd DePastino's academic reputation.