HTML5 + Javascript is really a great choice for a game engine, the performance isn't optimal, but that sacrifice is worth it for the portability
At the beginning of Construct 2 I held a very negative stance towards HTML5. Once C2 developed further and my own experience grew, there was a certain enthusiasm about being able to develop for almost any device. Only owning an older android device, I even went ahead and bought a Nexus tablet.
Unfortunately I was pretty soon disenchanted, because the performance was and still is a very fragile thing if you're trying something remotely advanced. Construct 2 heavily relying on third parties for exporting options to different platforms doesn't help the issue either. If there's a problem with these, it is not only out of your own control, but Scirra can't do anything about it directly either.
Overall it gives more of the impression of a bit of a mess rather than a great breakthrough in portability. To me at least.
Granted, it also depends on what kind of games you want to develop. C2 attracts a whole "new" group of developers, who want to make game apps. Casual games rather than, well, core games. I can see this being a good business decision for Scirra. At the same time I can't deny it makes me feel a bit alienated.
All I really want in C2 is a better editor sdk for plugin devs, and all the other features would then come from it eventually.
In a podcast interview not too long ago Ashley stated this would be one of the major things for Construct 3. I also got the impression that C3 might come earlier than expected and C2 will then stop being extended, but still maintained. Don't kill me please if I'm incorrect here.