Already controversy is brewing... Already businesses are starting to back away from bitcoin because if the block limit isn't raised then one of three things will happen: 1. Bitcoin fails. 2. Bitcoin gets used only for moving large amounts of money and other cryptocurrencies take over eventually displacing bitcoin itself. 3. Bitcoin gets used for only moving large amounts of money and "bitcoin clearing houses" fill the gaps, which increase the risk of fraud/theft/unaccountability, add avenues of attack, and form REAL centralization. Not some hypothetical BS.
1 - seems doubtful.
2 - seems 'so what?'
3 - seems that Bitcoin would fall into a role where it can provide a solid and reliable backstop against which other solutions may built and evolve. Some will be scams or maybe even fractional but those which don't work or are mis-managed will die and those which do and are well managed will thrive. Critically, Bitcoin may still be used...possibly at some cost...as a shuttle between competing solutions when the need arises.
Of course I would like to see Bitcoin be everything to everybody. Perfect in every way and all that. But it's not realistic. #3 would still be one hell of an achievement and a great leap forward.