I seriously doubt that most of us would spend as much on our hobby if we didn't expect to recoup a substantial portion of our investment. This seems especially true for those collectors who are willing to spend thousands of dollars to acquire a single coin. Unlike the new boat or motor home, our coins shouldn't drastically depreciate in value.
I once overheard a dealer tell a collector that there was “no future” in collecting modern commemoratives. The dealer called this material “garbage”. He then pointed to several coins in his display and began to explain why these objects were “real coins”.
It may well be that modern commemorative coins lack serious investment potential. I could have used several dozen other categories that may or may not be marginal as investments. I think it's important to realize that many collectors are interested in coins because collecting them is fun and having fun is their primary reason for participating in the hobby.
I don't advocate making impulsive purchases. Every collector should develop a collecting strategy. Having fun with coins can justifiably be all that matters. For example, since they were first issued in 1987 I've liked the nickel/bronze Canadian dollar coins. The size, shape and reverse design caught my attention and kept it. For no reason other than my fascination with the coins, I've built several sets and continue to add the new issues as they become available. To other dealers and collectors my sets of “little” dollars might not merit a second glance, but these coins are important to me and that is reason enough to collect them. I could say the same thing about my ancient coins, none of which cost me more than $20. If the market ever gets hot, and I seriously doubt it will happen, my entire collection of German tokens might fetch $500, but the monetary value of these pieces means nothing to me.
Even if you are a seasoned numismatist who has invested heavily in coins and is on the way to building a superb collection, I'd encourage you to begin collecting something merely for the fun of it. Sometimes it can be very refreshing to put rarity, value and condition aside and just have some innocent fun with the hobby.