Why would anyone do that ? But it's a good question.
To be clear, not anyone could do it. It would have to be the core developers who make the decision to do that, as they are the only ones that, in general can release/approve any code updates without forking the blockchain. The problem is, this change would be so dramatic and controversial, it's likely to fork the blockchain anyway, and throw the entire project into chaos. X% of people would whole-heartedly disagree, and fork the project with the original code and original philosophy. 100%-X% would just follow the core developers and go with it. I believe that this would cause all sorts of controversy, and frustration, and loss of morale among BTC supporters. It would probably start a downward spiral of BTC. I assume X > 10.
Only with an extraordinary level of "consensus," whatever that means, could the developers make such a drastic change and keep the unanimous support of the current user base. The problem is, there's not really a way to get a consensus. Even if the software design was truly a democratic process, there's no way to know what users would agree to do. I think the only way for Bitcoin to continue is with the core philosophical elements intact.
Other people have decided they don't like the way BTC works, and have made their own forks (one of them, I forget which, uses constant inflation rate). But to date, none of them have attracted any significant portion of BTC users, and thus, the devs have no reason to believe this is a desirable change (plus, they'd have to believe in it themselves, first).
