Stack Overflow [undefined] and the Stack Exchange network [undefined]
They're proper nouns; why do they need definitions?
help people find the answers they need [meaningless generic phrase]
I don't think this is meaningless nor generic. The network has the specific purpose of collecting answers to questions.
Comprising 173 Q&A communities [what comprises 173 communities? Stack Overflow, Stack Exchange or the Stack Exchange Network?], including Stack Overflow [what includes Stack Overflow?]
This isn't ambiguous.
- It's clearly not "Stack Overflow" since the subject doing the comprising is described as "including Stack Overflow."
- It's probably not "Stack Exchange" since that's not listed earlier on the about page.
- That leaves "the Stack Exchange network".
But even if "Stack Exchange" and "the Stack Exchange network" were both options, it wouldn't be confusing. People would mostly assume that "Stack Exchange" and "the Stack Exchange network" are the same thing, which (for the purposes of this page) they are.
Our products and tools empower people to find what they need to develop technology at work or at home [meaningless cheerleading text].
What else would you want? The company commercially sells three fairly different services; there's no good umbrella term for them. Besides, the details aren't the point of an "About Us"; if somebody wants the specifics of one of the services, they can check its individual page.
These products [what products? Stack Overflow, Stack Exchange or the Stack Exchange Network?] include Stack Internal and Stack Advertising.
The previous sentence used the word "products", so "products" here refers to the products referenced in that sentence. If that was confusing, the inclusion of "Stack Internal" and "Stack Advertising" demonstrate that the sentence is referring to the commercial products, not the free Stack Exchange network websites.