Use MyISAM for very unimportant data or if you really need those minimal performance advantages. The read performance is not better in every case for MyISAM.
I would personally never use MyISAM at all anymore. Choose InnoDB and throw a bit more hardware if you need more performance. Another idea is to look at database systems with more features like PostgreSQL if applicable.
EDIT: For the read-performance, this link shows that innoDB often is actually not slower than MyISAM: https://www.percona.com/blog/2007/01/08/innodb-vs-myisam-vs-falcon-benchmarks-part-1/