Hi there,
I apologise for the experience that you've had here but trust me this is not intended at all.
The spellcheck is as per the dictionary and the suggested corrections that you're getting are also from that dictionary only. It is in no manner affected by your frequently used words or region or the document content.
I request you to not feel offended by these suggested correction and you can anytime ignore these and use words that fit in your content the best.
If you still want, you can go ahead and write a feedback here: https://indesign.uservoice.com/ so that the team can assist you better.
Regards,
Sheena