think about it if you were a miner, and have learnt that you can charge XXX for transaction why would you be happy to again charge just one X?
It is certain the more popular coins will increase costs to catch up with bitcoin, as opposed to bitcoin lowering .
Developers are already being pressured to behave in ways that I dare not repeat.
Yes, I think what you say's true, cost's one of the factors that make most investors go away from bitcoin and switch to several other altcoins or maybe also go to other commodities, for example bonds, stocks, gold, and silver.