The other reason is that they feel that, without transaction rate limits, mining won't be profitable when the rate of coin subsidy drops off. Some argue that we need the competition for limited block space in order to drive fees up enough to keep mining profitable. Those same fees kill microtransactions.
Since a hard fork would require agreement from essentially everyone involved in Bitcoin, there's essentially no chance of this limit being increased.
The bitcoin network underwent a hard fork a couple weeks ago due to a bug in the implementation of the on-disk database.
The developers reached out to the mining pools and got the vast majority downgraded within 8 or 12 hours. A day or two later a new version was pushed out that mimicked the old behavior up until the point that a supermajority of nodes were upgraded, and then switched to the new behavior.
Forks have happened before, and the community is close-knit enough to resolve them. Everyone's primary goals are a) being ideologically neutral and b) keeping the network running, in equal measure.
That's simply not a lot of data anymore.
Secondly it also excels in that I can send money to someone I don't know for a service, and while they could disappear and run without me having much recourse, they can't steal/lose my bank details or credit card number. There's a different level of risk, one that pays off with small transactions rather than large. Credit cards are the other way, I'm unlikely to call mastercard to reverse a $0.2 transaction, and lots of the consumer protections (in the UK) only apply on certain size transactions.
To pay for something, I have to give someone enough information to take money out of my account. To send bitcoins to someone, it's up to me to send it.