Yes. If you want trivial plans to remain in the plan cache, you'd have to use a trace flag. This can be dangerous because it can bloat the plan cache to massive proportions, while simultaneously depriving the data cache and other parts of the buffer pool (depends a lot on the version of SQL Server as to which parts will be starved for memory, but always the data cache). And since trivial plans are so easy to create, SQL Server doesn't bother with them under normal circumstances.