CamelCase is also difficult for many readers (especially the non-English) to comprehend, so peppering your text with many just becomes a wall of gibberish. It's almost like forcing dyslexia on them.
(See WhatIsTmesis for an explanation of tmesis)
Hyperlinks also demand to be clicked on. Many Web users feel InformationOverload when they have not clicked on every link; often they will click on them before they are done reading what you wrote, which is probably not what you want.
Every time the possible path of reading bifurcates, you force the reader to decide which path to follow. No matter how quickly the reader makes this decision, it still complicates matters, dragging the process of reading. You should present essentially linear text unless you have something worthwhile to link to. It's even better in many cases to re-describe an idea across the whole hypertext; not only is this simpler to read and write, but it helps to reinforce the idea. There is undoubtedly a yet-to-be-written Law that measures the amount of time it takes a reader to read a link, decide to follow it, click on it, load the target, render it, and return to the original page and states that if it takes less time for the average reader to read the text of the target, you should just write it inline (a la an optimizing compiler's decision to inline a function).
Therefore, make it obvious to the reader which of your links are important, and demanded by your writing, and make these links rare and precious. You can also use HubAndSpoke links.
You can easily provide markers to help the reader quickly decide which links are most important. For example, inline links (Fred was born in <u>1992</u>) are less important than explicit links (see <u>meaning of life</u>) which in turn are less important than links with signs on them saying "read this" (for more information about this period of history, see <u>The Victorian Era</u>).
For most readers hyperlinks call attention to themselves in browsers away from the flow of text. They are also typically difficult to read, the standard being ugly bright blue and dark purple or inverted highlighting.
Therefore, use a stylesheet that gives links less emphasis - not underlining them, for example. Vary emphasis by using explicit links for important links, and a footnote for links of marginal importance.
Consequent to the desire to follow every link, experience shows that if you smash random phrases together, people will click on the link and then save something. Usually, this is an amazing thing. However, if the link isn't the name of a concept that needs further explanation, the result is a ShallowPage: spam. SeeAlso and Wiki:AtomicBomb are some examples. There's nothing that needs to be written about either, so there's no need confusing the reader with a link. Creating meaningless WantedPages does not improve things.
Therefore, do not create links to pages that do not exist and should not exist. Avoid meaningless wanted pages, and avoid shallow pages. If a link doesn't add anything to what you are writing, don't make it. It's just more junk the reader has to mentally filter.
On a wiki, titles are page names are links, so links do not always read as links, but as tokens representing a concept. You especially get this sense when you read a page repeatedly self-linking in its description, especially if it is a well-written Pattern. Cluttering the page with links means you are stringing together too many concepts together without any connecting glue. The reader then has to do the heavy lifting to understand why the separate pages are related. This is similar to someone dumping a sequence of figures into a textbook. A basic rule of writing is that all figures must be referred to and explained directly in the text; otherwise, the reader has to do the work of interpreting the data, which is the author's job. -- SunirShah
Another excellent way to avoid clutter links is to use correct English instead of a LinkPattern. For instance, do not repeat the title of the page as a link in the page; this also helps Google sort out the correct spelling of the page. Don't repeat a LinkPattern more than once. Instead, write it in proper English again. When the form of a word is a LinkPattern, such as some technical terms, surround the text in nowiki tags; e.g. <nowiki>InterNIC</nowiki> becomes InterNIC.
Of course, sometimes it's valuable to repeat a link multiple times. Some concept may be important enough to burn into readers' minds, like BarnRaising. This helps people remember page names of the site. Knowing when to do this takes judgment, and therefore experience, and thus is a matter of style. Just keep in mind no one can remember one duck in a flock of a thousand, but everyone can remember one ugly duckling in a flock of swans. If you keep the links rare, the ones you do put in will make an impression.
If your wiki encourages use of anchors (NamedAnchorsInWiki), then people may start reading halfway through the text, so links that appear to be multiple (and hence redundant) to the author may not appear redundant to the reader.
I have recently started to experiment with "explicit links" on the Oddmuse manual wiki  -- either use the footnote style for link, thus keeping them unobtrusive, or using explicit phrases borrowed from the texinfo manual :
I find this makes text easier to read, and it makes it obvious when too many links are being used. -- AlexSchroeder
I sympathise with dyslexics, but surely we've learnt to deal with the widespread proliferation of links by now? My approach is to open tabs whenever something piques my interest, come back to them as I have time, and occasionally have rapid culls. I prefer pages with lots of useful links, so I'm able to explore in all interesting directions. Explicit links, or footer links, are usually a distracting nuisance.
(56 tabs right now)