It looks really stupid to me. Use hyphenation only with justified text!

It does not look like a bad practice to me, at least in moderation; but then I only read text – I do not write any.

It's not a problem either way, but really depends on line length—hyphenation being added to shorter lines for a nicer rag.

Depending on the usecase, do it wisely, sparsely and/or to create visually appealing rags that also contribute to a proper outline leading to better readability. Try to use hyphens only in places that do not disturb the text's legibility (i.e. where two significant parts of a compound word meet, before/after pre-/suffixes, don't hyphenate proper names or in problematic cases like "anal-phabetic"). If you cannot spend time and effort to do it properly, avoid it completely. This question also relates to different languages and national/regional conventions or norms with regard to typesetting, which are in part defined by language structure – e.g. agglutinating languages will likely have to use hyphenation in order to avoid underfull lines.

Thanks for the reply all! It's good hearing from different perspectives.