Read this thing that the inventor of Bitcoin wrote:
https://bitcoin.org/bitcoin.pdfAnd then tell me where it says transactions are supposed to be free or cheap. If it's there, I'm not seeing it.
The problem is: The lower the fees, the higher the adoption rate. The masses wouldn't come if the fees are too high. And even worse: There could be cheaper competitors.
But as I already said above: It's not the miners' fault, it's the users that initiate the spiral that leads to higher fees.
Bitcoin was designed to have high transaction fees. The standard of 50 btc was set as an initial reasonable reward but the reality of financial reward is set by a different standard. Business (just like MasterCard, Visa, and banks transactions) fees will be set by the company based on the financial incentive they require to remain in business. That incentive is mensurate and can be calculated by including all factors relating to maintaining the business plus a reasonable profit margin. Equipment repair, replacement, employee cost, utility costs, land leases, business licenses, etc. are all included in the calculation.
Adoption rate, current number of users, number of transactions per block, btc price, operating cost of competing systems like MasterCard, are all immaterial to the business mining bitcoins. All they know is they need to meet their costs to stay in business. Sure those things will effect the cost of mining (like more people making transactions will mean a smaller fee for everyone) but the company doesn't care. All they care about is making X amount per block or they're not going to stay in business.
If you want to see a crazy high transaction fee just wait until public utility companies realize they can charge more for Bitcoin mining usage rates.
Utilities can and do use following rate structures:
Simple (or Fixed) Rate
Tiered (or Step) Rate
Time of Use (TOU)
Demand Rates
Tiered within Time of Use
Seasonal (4 Seasons)
Weekend / Holidays
Any combination of the above
I can see a day where global electric companies add a new category called: Cryptocurrency Mining Rate.
If they do you will look back at a dollar fee with a gleam in your eye because those were the good old days.