Would it be even remotely possible to force the change in sha256 bitcoin algorith to something else that asic and fpga devices couldnt compute?
No. For one thing, ASICs and FPGAs can be constructed for any computable function, ie, anything a CPU can do, an ASIC can be constructed to do it more efficiently. It's just a question of whether it's worth the development cost.
We started off with a bitcoin that anyone could use attack and now were attackers are forced to buy stuff we they dont really want.
This is the second thing. The purpose of mining is
not to allow "anyone" to create free money by burning spare CPU cycles all day. The purpose of mining is
to secure the network from attack. Nothing more. One of the larget threats is posed by mining botnets, and such botnets will have access to a lot of powerful CPUs and some decent GPUs, but almost certainly no suitable FPGAs or ASICs. Litecoin and other "CPU-friendly" coins are
ipso facto botnet-friendly, and there is a very real danger that an attacker with a reasonably sized botnet could pull off a 51% attack against Litecoin. On the other hand, by requiring specialised hardware to mine efficiently, Bitcoin also requires specialised hardware to attack efficiently, making it much more secure against attackers using conventional hardware.