> it benefits them only indirectly by making iOS a more attractive choice
Since you agree it benefits them - and your use of the word "only" is deceptive here; having the best app catalog is no marginal thing, it is an enormous benefit, often cited as the primary reason Android tablets have struggled and why WP7 failed - why don't you think that benefit - which exists primarily because HTML5 still sucks for mobile apps - incentivises them not to improve browsers?
It would be trivial for both Google and Apple to remove a large number of the barriers to HTML5 apps replacing native apps. But they don't, and it's been long enough that time is not an excuse.
Since you agree it benefits them - and your use of the word "only" is deceptive here; having the best app catalog is no marginal thing, it is an enormous benefit, often cited as the primary reason Android tablets have struggled and why WP7 failed - why don't you think that benefit - which exists primarily because HTML5 still sucks for mobile apps - incentivises them not to improve browsers?
It would be trivial for both Google and Apple to remove a large number of the barriers to HTML5 apps replacing native apps. But they don't, and it's been long enough that time is not an excuse.