Fortunately, engineers are a significant target market.

In the real world, simplistic ticketing systems fail to meet enterprise needs, which are complex and peculiar, arising from weird contract clauses, irrational political outcomes, legacy processes etc etc. JIRA's multi-layered customisability is a huge boon in these environments.

Also, people aren't actually stupid. Yes, even non-engineers can use a complex piece of computer software! A little training goes a long way. Who knew?!