Not correct at all. Immigration has the right to denie entry. A visa is issued by an embassy or consulate which are parts of the MFA. Immigration is a part of The Royal Thai Police. They can see your history as a tourist, and if they think you're abusing the system,they can denie entry. Period.
It's about the time you spent in Thailand and if you extended the stay another 30 days and maybe did border runs.That's when immigration might start asking questions on your next arrival.
Two weeks at the time will never be a problem. But staying 60 days on a visa exempt + one extension and maybe a border run on top of that and THEN coming back on a new 60 days visa exempt. Now you "might" have a problem with immigration.