I think it was 100% necessary to get it going, but just thinking about the 50% cut every 4 years that's like quitting hard drugs cold turkey, it not like any business invests in new infrastructure with a guaranteed 50% cut in income is a great business to get into even if you can price it in.
to be honest I was even a little apprehensive at the first halving, I thought it would be too much of a shock, I kept mining only because the price went up, all in all there are lots of well balanced incentives and while I've fantasized how my ideal alt would work I learn why something is the way it is.
If I thought it was worth going through the argument, I'd be in favor of a protocol change to make the block reward shrink a little bit each block instead of suddenly dropping by half every four years.
Really though it's only the first 3-4 block reward halvings that we need to worry about. After that it should be small enough to not matter any more.