I do not think a 51% attack would mean the end. The pool would have to have a malicious intent. The people in the pool, probably would switch over to another pool (or the smaller pools could form together).

The 51% attack could only affect future blocks and not past blocks so, people could just stop using btc or blockchain could shut down until issue is resolved.

New modifications can prevent future attacks. I just do not see it as a serious threat. Does anyone agree with me on here (or am I missing something?)