IMHO, I think what he was saying was... "Possible trouble with the campground electrical post"
The initial logic is that the 30A plug is the most common and gets worn out more that the 50A. Worn electrical connections can cause problems for your unit.
Invest in electrical protection, not just a surge guard.
I have a 30A TT and a commonly called "dogbone connector". It is a short thick extension cord that plugs into the female 50A plug on the the post with a 30A female connector for my TT cord. I use it when stuck at a 50A only site or when there is trouble with the electrical service. Troubles can happen at a campground that is packed during the hot summer and people are taxing the electrical grid running ACs.
If you have troubles with the 50A, move... Remember a surge guard will not warn you of all electrical troubles and may not not protect you from them.
I know others here can say this better and in more detail than I.