The complete sentense is "On average, the more public member functions are, the harder it is to find bugs — and please don’t get us started on the complexities of debugging classes with public data."
I've found some similar phrases, but they don't fit in this context:
- start on - to begin dealing with someone or something (but then why "started on"?)
- get smb to do smth
- don't get me started - Used to attempt to avoid or abbreviate a discussion that speaker or hearer may wish to avoid.