You should read this discussion. A lot of what you are worried about was discussed there.
The condition issue is definitely real, which is why grading has increased, and why a lot of serious collectors buy already graded cards. Certain set cards do not matter as much, but the rarer ones people want in actual mint condition. Collectors who value condition are tired of buying cards falsely described as mint. It is something that has been increasing for the past few years.
The only other worry, the main worry, are fast money sellers who pop up during the boom. They are temporary and have no connection to the hobby. Also, those are typically the ones who will deal unscrupulously as they do not have any value outside of monetary gain. When dealing in hobbies, understanding is everything, not just knowledge. Knowing which cards are popular is easy, everyone can search ebay competed listings. Being able to provide sound advice only comes from being engaged beyond, “what is this worth (so I can list it on ebay)”.
The easiest way to find out if people are actually engaged, check their collection. If they actually collect cards, that is a good sign. If they use the term “collection” as a replacement for “inventory” then they are the problem. The irony is that people who are trying to make a quick buck and constantly sell are failing on both fronts; they are neither a collector or an actual business. First, they are obviously using communities knowledge, literally like parasites. Second, if everyone constantly bought and sold, the market would disappear. In this hobby, actual businesses need collectors, and vice versa. However, businesses could not exist without collectors providing a consistent demand, more specifically, holding cards.
People who have an actual inventory, pay taxes, understand supply & demand, have an understanding of a hobby, oh and again, pay taxes are an actual business. If you don’t pay taxes, you aren’t a business. The fast money guys are not business men, they are typically young people who have ambition, and are primarily driven by greed. Businesses require proper capital, and patience. Usually the quick money guys can’t afford to properly hold cards, and in turn, they saturate the market. If no one holds their items, the market deteriorates.
I wouldn’t worry about people being nostalgic, that is nothing new. It has been around probably as long as humans had the cognitive ability to reflect on the past.