I do not understand how anybody can make a text search engine ux that is bad in this day and age. Have the people who create such broken abominations never used, I don't know, you know, Google? There are 3 (yes, three) basic levels of epic fail that I constantly find on the internet:

1. No free text search feature at all.
2. It is just broken under the covers (e.g. bad index no stemming or god only knows what) so good results are hard/impossible to get (e.g. I see the thing right in front of me but search doesn't find it) (e.g. hits appear and disappear seemingly randomly as I update my search).
3. Front end search query language is weird (e.g. doesn't default to 'and') (e.g. uses extra weird syntax).
4. Really poor filtering options (e.g. none, or stupid wrong ones).

e.g. Jira, Confluence, GitHub, Craigslist, Android Gmail, Win Phone Edge, most any e-commerce site I've ever seen ever, etc.