At a big corporate, we had an Apache Solr based search which had some reasonably clever lemmatization and stats analysis and spell check config to suggest alternative searches if not many results were found for the original query, but one day someone reported an unfortunate edge case which caused a bit of a panic - if you searched "annual report” it returned "did you mean anal report?" (we were in the finance sector rather than medical sector, but there were a lot more documents in the corpus containing words like analysts, analysis, analytics etc). Anyway, the point is yes, it is great to have that sort of functionality, but it does come at a cost, and a small project like this might prefer to keep it simple.
Generating suggestions from something other than what your users have already given you is inevitably going to result in something different and potentially offensive being shown to them.
One solution is to offer suggestion from a list of previous searches.
Also, that is very much a big corporate problem: I imagine most searchmysite users are mature and stable enough not to have a melt down at the word "anal".
But I agree with your point, sometimes seemingly small features take a disproportionate amount of support, and this could be one of them!
Couldn't you just add an extra step to check if the suggestion is offensive, then don't show it?